Firms dealing with Iran to be barred from US: Trump

LONDON: Companies doing business with Iran will be barred from the United States, President Donald Trump said on Tuesday, as new US sanctions took effect despite pleas from Washington's allies.

Iran dismissed a last-minute offer from the Trump administration for talks, saying it could not negotiate while Washington had reneged on a 2015 deal to lift sanctions in return for curbs on Iran's nuclear programme.

"These are the most biting sanctions ever imposed, and in November they ratchet up to yet another level. Anyone doing business with Iran will NOT be doing business with the United States. I am asking for WORLD PEACE, nothing less!" Trump tweeted on Tuesday.

Iranian Foreign Minister Mohammad Javad Zarif criticized Trump's tweet as a tired cliche and denounced "US unilateralism." "And it is not the first time that a warmonger claims he is waging war for 'world peace'," Zarif tweeted.

White House national security adviser John Bolton said on Monday Iran's only chance of escaping sanctions would be to take up an offer to negotiate with Trump for a tougher deal. "If the ayatollahs want to get out from under the squeeze, they should come and sit down. The pressure will not relent while the negotiations go on," Bolton, one of the administration's main hawks on Iran, told Fox News.

On Tuesday, Bolton said the sanctions were already working, deterring European companies: "The European governments are still holding to the nuclear deal, but honestly their businesses are running from it as fast as they can so that the effect of the American sanctions really is proceeding regardless."