Germany's vice chancellor Sigmar Gabriel met Russian President Vladimir Putin late Wednesday, with the crisis in Syria high on the agenda.
Referring to "difficult times" for the war-torn country at the start of his meeting with the Russian leader, Gabriel described an attack on an aid convoy in Syria this week as "the worst thing that he could have imagined."
The attack on the convoy killed more than 20 people and heralded the collapse of a ceasefire brokered by Russia and the United States.
The possible easing of European Union sanctions would also feature in the high-level talks, Gabriel said earlier.
Gabriel, economy minister and deputy to Angela Merkel, has repeatedly criticized the German chancellor's determination to maintain EU sanctions against Russia, which were imposed in the wake of its annexation of Ukraine's Crimean peninsula.
Putin described Germany at the start of the talks as an important trade partner for Russia.
"We must find solutions to all difficult questions," Putin added.
Gabriel, visiting alongside a German trade delegation, is a member of the Social Democrats (SPD) - junior coalition partner in Merkel's conservative coalition - and may run for chancellor in next year's general election.
His visit to Russia has sparked controversy at home. The Kremlin has repeatedly been criticized for attempting to sow discord within the German government and the general public.
A report on Russian television in February that a Russian-German teenager had been raped by migrants sparked anti-government protests in several German cities.
Suggestions from the Kremlin that there had been a cover-up by German police caused the already-strained relationship between the two countries to deteriorate further.
Though controversial in the context of infighting within Merkel's coalition, Gabriel's visit is being cheered on by German business leaders, who are keen to return to trading with Russian partners.
The Russian-German Chamber of Commerce's Matthias Schepp referred to Gabriel's visit to Moscow as a "sign that Germany and Russia want to remain in talks despite political tensions."
Schepp referred to the EU sanctions as "counterproductive," adding that "German business is hoping for increased support from Berlin."
Earlier this week, Gabriel survived a vote by delegates of his centre-left Social Democrats on a controversial EU-Canada trade deal that he has championed as the bloc's best chance to shape globalization.
The vote had been interpreted by German media as a referendum on Gabriel's hopes of challenging Merkel in the September poll.