Ukrainian President Volodymyr Zelenskyy told an international summit in Sweden on Monday it is a "critical moment" to support Kyiv, amid U.S. peace proposal negotiations.

It came as European Union leaders met in Angola to discuss the situation in Ukraine, on the sidelines of a scheduled summit with the African Union.

On Sunday, U.S. Secretary of State Marco Rubio and top Ukrainian officials held talks in Geneva over the American 28-point proposal to end the war in Ukraine, which sparked alarm in Kyiv and European capitals due to its initially favorable terms for Russia.

Ukrainian President Volodymyr Zelenskyy said on Monday he is "working closely with the United States, with European partners with many, many others to define steps that can end Russia's war against us, against Ukraine, and bring real security."

"There is a lot of noise in the media, a lot of political pressure, and even greater responsibility for the decisions ahead," he added.