LONDON - US President Donald Trump said on Monday that he is "very disappointed" with Russian President Vladimir Putin and that he is considering shortening the 50-day deadline he previously set for a ceasefire deal in Ukraine.

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Trump made the remarks ahead of talks with British Prime Minister Keir Starmer in Scotland.

Speaking to reporters before heading indoors, Trump said that he may shorten the deadline he had previously imposed.

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"We're going to have to look. I'm going to reduce the 50 days ... because I think I already know the answer," he added.

Earlier this month, Trump threatened to impose "very severe" tariffs on Russia if a ceasefire deal was not reached within 50 days.