BBC News with Ian Purdon.

The US Interior Secretary Ken Salazar has sharply criticised the oil company BP for its handling of the huge oil leak in the Gulf of Mexico. Speaking after a visit to BP's American headquarters in Houston, Mr Salazar said he was angry and frustrated that BP has missed deadline after deadline to stem the flow of oil. He said the disaster represented a crucial challenge for the company.

“I have no question that BP is throwing everything at the problem to try to resolve it because this is an existential crisis for one of the world's largest companies. Do I have confidence that they know exactly what they are doing? No, not completely. “

Earlier a spokesman for BP admitted that efforts to reduce the flow of oil had not been working as effectively as before. The BBC Washington correspondent says the tough rhetoric from the White House is in part a response to increasing public frustration with the way the federal government is handling the crisis.

Iran has suggested that Washington propose a prisoner swap in return for the release of three Americans held in Tehran accused of spying. The Americans say they entered Iran accidentally while hiking in northern Iraq last year, but the Iranian authorities have ignored repeated (fleas XD)pleas for their release. From Washington here is Bahman Kalbasi.

The intelligence minister did not name any specific Iranians being held in American prisons who could possibly take part in a prisoner exchange, but he said Iran had made a humanitarian gesture in allowing the three American prisoners’ mothers to visit last week and the US should make a similar move. Responding to the comments, a US State Department spokesman said there had been no discussion between the two countries about any potential swap. He added the US believed the spying charges against the 3 young Americans are, in his word, ridiculous, and they should be released immediately.