Russia on Monday contradicted claims by Syria that an offensive to recapture rebel-held areas of the country's largest city, Aleppo, was imminent.

On Sunday, Syrian Prime Minister Wael al-Halqi said a joint operation was being planned to take the city's rebel-held eastern sector.

Activists based around the northern city said that Russian and Syrian aircraft have been increasingly active in the area.

But the head of operations for the Russian General Staff, Sergey Rudskoy, said that activity was aimed at disrupting plans by jihadists to besiege government territory.

"No onslaught on Aleppo is planned," Rudskoy said Sunday in remarks reported by the official TASS news agency.

Rudskoy said Russia had information that al-Nusra militants were planning a large-scale operation south of Aleppo to cut off the government's only supply route into the city.

"That is why all activity of the Syrian troops and the Russian warplanes is aimed at disrupting the plans," he added.

Recent weeks have seen rebels led by Syrian al-Qaeda affiliate the al-Nusra Front win back ground south of Aleppo from government forces.

Analysts have suggested that the setback for the government, which reportedly fought without Russian air backing, may indicate that Moscow is seeking to put pressure on Syrian President Bashar al-Assad to engage seriously in peace talks due to start in Geneva on Wednesday.

A fragile ceasefire has been in effect in Syria since late February, but jihadist groups such as al-Nusra and the Islamic State extremist organization are not covered by its terms.

The US is "very, very concerned about the recent increase in violence," US State Department spokesman Mark Toner said in Washington, adding that there have been "actions we believe are in contravention to the cessation of hostilities."

He went on to note that "the vast majority of violations have been on the part of the regime."

Government forces control the western part of Aleppo, while a patchwork of rebel groups holds the eastern sector.

North of the flashpoint city, a monitoring group reported that Islamic State fighters recaptured a string of villages from rebels who had been trying to cut off its access to the Turkish border

According to the Britain-based Syrian Observatory for Human Rights, Islamic State regained control over al-Rai village, which rebels say is an important smuggling route for the extremists.

The head of the Observatory, Rami Abdel Rahman, told dpa that the rebels also lost six additional villages, reversing much of last week's gains.

"This is considered a great loss for the rebels, and it proves that without airforce backing no one can hold grounds," Abdel Rahman said.

The opposition fighters initially captured al-Rai with the help of US-led airstrikes, rebels have told dpa.

Also on Monday, UN Special Envoy to Syria Staffan de Mistura met with Syrian officials to discuss the upcoming peace talks and humanitarian issues.

"The Geneva talks' next phase is crucially important because we will be focusing in particular on political transition, on governance, and constitutional principles," de Mistura said after a meeting with Syrian Foreign Minister Walid al-Moallem.

He said he hoped that the upcoming talks would be "constructive."

The talks are aimed at ending the five-year long struggle which has so far left more than 260,000 dead, according to figures compiled by the Observatory.

The Syrian opposition has insisted repeatedly that there can be no future role for al-Assad.

State news agency SANA quoted al-Moallem reiterating Syria's commitment to "an intra-Syrian dialogue led by Syria without preconditions."

De Mistura also discussed the fragile ceasefire which had come into effect in Syria on February 27.

"We did raise and discuss the importance of protecting and maintaining and supporting the cessation of hostilities ... and we need to make sure that it continues to be sustained even when there are incidents to be contained," he said.

De Mistura and al-Maollem further tackled the issue of humanitarian access to all areas in Syria.

The UN World Food Program on Sunday successfully airdropped food and medical supplies to government-held areas of Deir al-Zour in eastern Syria, the first UN aid to reach the city since March 2014.

According to the UN Office for the Coordination of Humanitarian Affairs (OCHA), around 200,000 people are living there under a siege imposed by the Islamic State.

The aid that was dropped into Deir al-Zour will feed only 2,500 people for one month, but the agency says it plans more drops soon to relieve "critical food shortages."

Latest news

Syrian opposition rules out future role for President al-Assad

The Syrian opposition said Friday it would not accept any role for President Bashar al-Assad in the future of the war-torn country, reacting to a recent US shift saying that removing al-Assad is no longer a priority for Washington.

Russian Army integrates breakaway forces of Georgian province

Parts of the small fighting forces of the Georgian breakaway province of South Ossetia have been placed under Russian military control, Russian Defence Minister Sergei Shoigu said on Friday.

Czech Republic's Pilsner Urquell beer is now Japanese

Japanese brewing company Asahi completed its takeover of the Czech brewery Pilsner Urquell on Friday, Asahi said in a statement.

Judge approves 25-million-dollar settlement of Trump University case

A US district judge on Friday approved a 25-million-dollar settlement of lawsuits and state fraud allegations against Trump University, the US president's now-defunct business venture.

Former Thai premier Thaksin to junta on reconciliation: 'Cut me out'

Former Thai prime minister Thaksin Shinawatra on Friday announced that he is not interested in the junta-led reconciliation process, three days after the junta handed him a half-a-billion-dollar tax bill for his past business deal.

Dalic: We welcome possible deal between Agrokor and banks

The government welcomes the possibility of an agreement being concluded between the Agrokor food company and creditor banks, and the bill on vitally important companies is not a fallback plan but the result of the government's care for the overall economic and financial stability of Croatia, Deputy Prime Minister and Minister of Economy Martina Dalic told a press conference in Zagreb on Friday.

Croatia, China sign action plan for cooperation in agriculture

The Croatian and Chinese ministries of agriculture on Friday signed an action plan for cooperation in the field of agriculture for the period 2017-2018, the Croatian ministry said in a statement.

ZSE indices up, Agrokor shares in focus of investor interest

The Zagreb Stock Exchange (ZSE) indices on Friday rose by more than 1.8%, with stocks of the Agrokor food and retail concern being in the focus of investor interest again.

Berlin police defend handling of Berlin market attacker

Berlin police defended themselves on Friday against accusations that they stopped surveillance on Berlin Christmas market attacker despite knowing in June 2016 he was dangerous.

Croatia, creditors tailor emergency measures to save tottering giant

Croatia's tottering retail and food giant Agrokor reached an agreement with its creditors, putting its debts standby and allowing it to continue working during emergency restructuring, the Croatian branch of Austria's Erste Bank said Friday.

Agrokor's creditors say standstill agreement to go into force today

A standstill agreement regarding the Agrokor concern's existing financial obligations to banks will take effect on Friday, additional capital will be injected into the concern in the coming days and the concern will be actively restructured, which includes a change of its management, it was said on Friday after a meeting between Agrokor's suppliers and creditor banks.

Palestinians, UN slam Israel's new settlement plan

Palestinians, Israeli activists and the UN lambasted the government of Israeli Prime Minister Benjamin Netanyahu on Friday, a day after it gave the go-ahead for the first new West Bank settlement in a quarter of a century.

South Sudan rebels release three abducted foreign oil workers

South Sudanese rebels have released three foreign engineers they abducted in early March in the oil-rich Upper Nile region, Foreign Affairs Ministry official Mawein Makol Arik said on Friday.

Turkish opposition: Imprisoned party chief has gone on hunger strike

The head of Turkey's pro-Kurdish opposition party has launched a hunger strike from prison.

European leagues threaten Champions League schedule clashes

The European Professional Football Leagues (EPFL) on Friday threatened schedule clashes on Champions League matchdays in an ongoing dispute with the governing body UEFA.

Danish court revokes citizenship of IS volunteer

A Danish appellate court on Friday stripped a man of his Danish citizenship for volunteering to fight for the extremist Islamic State in Syria.

Banks and Agrokor agree on key elements of standstill agreement

Member banks of the coordinating committee of financial creditors and representatives of the Agrokor food company have in principle agreed on key elements of a standstill agreement, which is expected to be signed later today, announcing changes in the company's management team, Erste Bank said in a statement on Friday afternoon.

Syrian man on trial in Sweden; mosque attack labelled terrorism

A Syrian man went on trial Friday in the southern Swedish city of Malmo, charged with terrorism and arson after an attack last year on a building used as an assembly hall by Shiite Muslims.