U.S. President Donald Trump says he has called Russian President Vladimir Putin and begun to arrange a meeting between Putin and Ukrainian President Volodymyr Zelenskyy, a critical step toward bringing a possible end to Russia's war on Ukraine.

In a reversal only few hours after meeting Russian President Vladimir Putin, Trump said an overall peace agreement, and not a ceasefire, was the best way to end the war. That statement echoed Putin’s view that Russia is not interested in a temporary truce, and instead is seeking a long-term settlement that takes Moscow’s interests into account.

President Trump and European leaders met for a one-of-a-kind summit at the White House on Monday to push toward a peace deal between Russia and Ukraine. But by the end of a marathon day of meetings, details on what such an agreement might entail remained elusive.

Trump complimented Zelenskiy on his black suit in a briefing punctuated with smiles and laughter. It was a much different scene than their chilly meeting in February, when the Ukrainian president's military-style attire in the Oval Office drew ire.

President Donald Trump was asked in the Oval Office about security guarantees for Ukraine and whether that will involve the U.S.

Ukraine will promise to buy $100bn of American weapons financed by Europe as part of a deal to obtain US guarantees for its security after a peace settlement with Russia, according to a document seen by the Financial Times.