French President Emmanuel Macron and German Chancellor Friedrich Merz have voiced severe scepticism about efforts by the US government and its envoys to negotiate a peace between Ukraine and Russia, according to a transcript of a confidential call cited by German magazine Spiegel.

In a report on Thursday, Spiegel said that during the call with Ukrainian President Volodymyr Zelensky and other European leaders, Macron warned that the United States could"betray" Kyiv when it comes to territorial concessions and guarantees to secure any deal.

"There is a chance that the US will betray Ukraine on territory without clarity on security guarantees," he said, according to the magazine.

In the call that took place on Monday, Merz warned Zelensky that US negotiators are"playing games" and that he should be "very careful" for the next few days, the Spiegel report said.

Berlin declined to comment, while the French president's office did not immediately respond to a request for comment.

European leaders on Monday rallied to show support for Zelensky after US-Ukrainian talks to revise a peace proposal that initially favoured Russia.