British Prime Minister Keir Starmer has reportedly blocked a request from US President Donald Trump to allow US forces to use UK air bases during any preemptive attack on Iran, owing to concerns it would be in breach of international law,

President Trump has warned Iran that an attack would be "far worse" than the U.S. airstrikes that targeted its nuclear facilities last June.

The U.S. buildup in the Middle East has reached a critical mass that could put pressure on Iran in negotiations. And, Trump unveils big plans for Gaza during the first-ever Board of Peace meeting.

The president was considering a range of military options but has said he still prefers diplomacy.

Rarely in modern times has the United States prepared to conduct a major act of war with so little explanation or public debate.

US President Donald Trump delivered his latest ultimatum to Iran on Thursday during a meeting of the Board of Peace, the Middle East coalition Trump formed to stabilise a region he could soon plunge into a new, weeks-long war.

As Trump pressures Iran, he's spoken of an "armada" heading for the Mideast, but there's another massive movement of American fire power in the air.

Trump readied the military for potential strikes on Iran. Trump officials proposed a WHO replacement. Background: Trump withdrew the United States from the World Health Organization last year, and the proposal would re-create WHO systems to which the U.S. no longer has access.