US President Donald Trump lashed out at the leaders of both warring parties in Russia's invasion of Ukraine, expressing frustration as efforts to kick-start ceasefire talks remain deadlocked.

As the war morphs into a deadly routine, it's harder for him to hold the attention of allies, and to keep people like Trump on his side.

Talks between Russia and the U.S. have failed to produce a ceasefire. Several partial ceasefires have been negotiated, but both sides have broken them.