US President Donald Trump on Monday threatened Russia with sanctions and secondary tariffs if they do not end the Ukraine war in "about 10 or 12 days," much earlier than a previous deadline.

"I'll announce it probably tonight or tomorrow, there's no reason to wait," he told a joint news conference with British Prime Minister Keir Starmer at one of the president’s commercial golf clubs in Scotland. His previous deadline of 50 days would have fallen around early September.

"It would be sanctions and maybe tariffs, secondary tariffs," said Trump on the possible consequences on Russia, but added he would do so reluctantly as “I love the Russian people, they're great people."

Labelling the war a "really bloody war," the US president underlined that reaching a ceasefire deal would be "common sense."

He went on to say though on three occasions they seemed close to a ceasefire, then "all of a sudden missiles are flying into (Ukraine’s capital) Kyiv ... What's that all about?”

He added, voicing frustration: "This has happened on too many occasions and I don't like it."