German Chancellor Olaf Scholz has urged Russian President Vladimir Putin to begin talks for a "just and lasting peace" with Ukraine, in the pair's first phone conversation in nearly two years.
However, the call prompted condemnation from Ukrainian President Volodymyr Zelenskyy, who described it as opening "Pandora's box".
The Ukrainian foreign ministry described Mr Scholz's call as an "attempt at appeasement".
Russian forces began a full-scale invasion of Ukraine in early 2022 and in recent months have been making steady territorial gains in the country's east.
In their one-hour phone conversation, their first since December 2022, Mr Scholz also demanded Mr Putin withdraw Russian troops from Ukraine and reaffirmed Germany's continued support for Ukraine, a German government spokesman said.
"The Chancellor urged Russia to show willingness to enter talks with Ukraine with the aim of achieving a just and lasting peace," the spokesperson said in a statement.
"He stressed Germany's unbroken determination to back Ukraine in its defence against Russian aggression for as long as necessary," the spokesperson added.
Mr Scholz spoke with Mr Zelenskyy ahead of his call with Putin, the spokesperson said, and would brief the Ukrainian leader on the outcome afterwards.
A source within the Ukrainian president's office told Reuters Mr Zelenskyy had tried to warn Mr Scholz against holding the call.
Germany is Ukraine's largest financial backer and its largest provider of weapons after the United States, whose future support for Kyiv appears uncertain following Donald Trump's victory in the US presidential election.
Scholz warned not to call Putin, Ukrainian source says
After the call, a spokesperson for the Kremlin said Mr Putin told the German chancellor any peace agreement between the two countries would need to be based on "new territorial realities".
The spokesperson described the call as "detailed and frank" and said Mr Putin made it clear any negotiations would have to address the root causes of the conflict.
Mr Putin has long argued Ukraine's interest in joining NATO prompted Russia to launch what he dubbed a "special military operation".
After Mr Scholz's office revealed the call, Ukraine's foreign ministry said the call was an "attempt at appeasement".
And a source in Ukraine's presidential office told Reuters Mr Zelenskyy believed it would only help Mr Putin.
"The chancellor told our president he plans to talk to Putin," the source said.
"The president said this would only help Putin by reducing his isolation.
"Putin doesn't want real peace, he wants a break."
"Talking to him will let Putin change the scenery and keep the war going.
"It won't bring peace because Putin will just repeat the lies he's been telling for years, making it seem like he's no longer isolated.
Mr Scholz's call comes after the collapse of his governing coalition last week, which has prompted snap elections in Europe's largest economy.
Reuters/AFP