Kuala Lampur, April 13 --  

WASHINGTON, April 13 - The US military said yesterday it would begin a blockade of all Iranian ports within hours, after peace talks in Pakistan collapsed with Washington blaming the Islamic Republic's refusal to abandon its nuclear ambitions.

The announcement came despite a ceasefire agreed on Wednesday aimed at pausing the six-week war until April 22, with tensions centered on whether the United States can force Iran to reopen the strategic Strait of Hormuz, another of its key demands in the stalled negotiations.

"The blockade will be enforced impartially against vessels of all nations entering or departing Iranian ports and coastal areas, including all Iranian ports on the Arabian Gulf and Gulf ...