"They agreed this is a critical moment for the course of the conflict, and there is an opportunity to turn the tide in the war," a Downing Street spokesperson said in a statement.

Both men "stressed the need to support Ukraine to strengthen their hand in both the war and any future negotiations. President Macron praised the Prime Minister's ongoing military support to Ukraine and the leaders agreed to step up this work," the spokesperson said.

(Writing by William Schomberg; Editing by Toby Chopra)