Washington/Moscow/Kyiv: US President Donald Trump said after his call on Monday with President Vladimir Putin that Russia and Ukraine will immediately start negotiations for a ceasefire, but the Kremlin said the process would take time and the US president indicated he was not ready to join Europe with fresh sanctions to pressure Moscow.

In a social media post, Trump said he relayed the plan to Ukraine's President Volodymyr Zelenskiy as well as the leaders of the European Union, France, Italy, Germany and Finland in a group call following his session with the Russian leader.

"Russia and Ukraine will immediately start negotiations toward a Ceasefire and, more importantly, an END to the War," Trump said, adding later at the White House that he thought "some progress is being made."

Putin thanked Trump for supporting the resumption of direct talks between Moscow and Kyiv after the two sides met in Turkey last week for their first face-to-face negotiations since March 2022. But after the Monday call, he said only that efforts were "generally on the right track".

"We have agreed with the president of the United States that Russia will propose and is ready to work with the Ukrainian side on a memorandum on a possible future peace accord," Putin told reporters near the Black Sea resort of Sochi.

While the indications that Ukraine and Russia will continue direct contacts speak of progress after more than three years of the war, the Monday flurry of talks again failed to deliver on expectations for a breakthrough.

European leaders decided to increase pressure on Russia through sanctions after Trump briefed them on his call with Putin, German Chancellor Friedrich Merz said in an X post late on Monday.