Ukrainian President Petro Poroshenko said Tuesday that Russia nearly caused a new disaster reminiscent of Chernobyl by waging war near a power plant in eastern Ukraine.
"Let us not forget that hostilities were held several hundred kilometres from the [power plant in Zaporizhia]," Poroshenko said in a speech dedicated to the 30th anniversary of the worst nuclear disaster in history.
"Russia was preparing a full-scale war against Ukraine. At least it planned military action and chaos in most parts of our country," Poroshenko said at the Chernobyl plant, according to a transcript posted on his website.
Moscow has supported a pro-Russian separatist rebellion in eastern Ukraine since Kiev ousted its pro-Russian president two years ago amid a protest movement that called for closer ties with the West.
Russia also occupied and annexed southern Ukraine's Crimea region in response to that president's ouster, and bilateral ties quickly plummeted to an all-time low.
Moscow has repeatedly denied Kiev's accusations that it has provided active troops or weapons to the rebels.
In New York, Volodymyr Yelchenko, Ukrainian ambassador to the United Nations, told dpa that the expenditures related to the conflict with Russia has also diverted resources that would have otherwise been used to restore and contain the Chernobyl site.
"Many things which are now about to be completed would have been done let's say two years ago. For example, the shelter facility, the sarcophagus, was supposed to be completed almost two year ago," Yelchenko said.
Poroshenko also noted that Russia's aggression had undermined the trust of non-nuclear states in the nonproliferation of nuclear weapons. Ukraine gave up its nuclear weapons - estimated at the time to be the world's third-largest stockpile - after the dissolution of the Soviet Union upon an agreement with Russia, Britain and the United States that its national security would be assured.
Ukraine has repeatedly cited the agreement, known as the Budapest Memorandum, in its calls against Russia following the Crimea occupation.
Poroshenko also signed a decree Tuesday to turn a large part of the Chernobyl Exclusion Zone into a nature reserve, according to a statement on his website.
The area, near the Belarusian border in northern Ukraine, will be known as the Chernobyl Radiation and Environmental Biosphere Reserve and is an "important step in the revival of territories contaminated by the man-made disaster," according to the statement.
Earlier this week, The Telegraph newspaper reported that the Chernobyl zone has de facto become one of the world's biggest nature reserves, as the lack of humans in the area has enabled animal populations to thrive despite the threat of radiation poisoning.
Radiation increases potential risk to animals, whereas humans present a more immediate risk by taking over habitats and hunting, the British newspaper quoted wildlife expert Nick Beresford as saying.
The international community has contributed more than 2 billion euros (2.26 billion dollars) to cleaning up and preventing further contamination at Chernobyl, according to the European Commission.
"Chernobyl led to a leap forward in global cooperation on nuclear safety," said Yukiya Amano, head of the International Atomic Energy Agency (IAEA).
The key lesson from Chernobyl and the 2011 nuclear disaster in Fukushima, Japan, was that governments, authorities and nuclear plant operators must not take safety for granted, Amano said in Vienna.
"Complacency must be avoided at all costs," Amano said.
After the accident, countries began sharing safety know-how, and have since adopted a set of rules called the Convention on Nuclear Safety and set up a process to review each other's safety record.
On April 26, 1986, a malfunction during a system test of the plant's Reactor Number 4 set off a series of explosions that sent thousands of tons of radioactive material into the atmosphere.
About 100,000 residents were evacuated from the surrounding area in what were then the Soviet republics of Ukraine and Belarus, while about 600,000 Soviet workers strove to decontaminate the territory and erect a sarcophagus made of lead and concrete to contain the radiation within the damaged reactor.
The sarcophagus, which was built in a rush, was never intended as anything other than a temporary solution. A new steel-based structure is being built to better enclose the reactor.