Washington, Jan 25 (IANS): Senator John Kerry, President Barack Obama's pick to replace Hillary Clinton as secretary of state, sailed through his hearing at the Senate Foreign Relations Committee that he chairs.

With Kerry, a Vietnam veteran and a senator since 1985, on the other side of the table, Thursday's hearing was led instead by Senator Robert Menendez of New Jersey.

During the five-hour hearing, the 2004 Democratic presidential nominee who lost the election to George W. Bush, said "we will do what we must to prevent Iran from obtaining a nuclear weapon".

"I repeat here today: our policy is not containment. It is prevention and the clock is ticking on our efforts to secure responsible compliance," he told the panel.

He said he hoped the US and its allies would maintain diplomatic pressure against Iran, but said Iran had to prove its nuclear programme was solely for peaceful purposes.

There are sanctions and they are working, he said, noting Iran's currency, the rial, has dropped, and other nations have been cooperating in reducing dependence on Iranian oil.

In response to a question by Democrat senator Jeanne Shaheen, who led a trade mission to India about a year and a half ago, Kerry said "foreign policy is increasingly economic policy".

"And I think there's much more we can do to augment our engagement with the private sector and their desires and needs abroad."

Asked if he would consider supporting conditioning aid to Pakistan on the release of Shakil Afridi, who helped to find Osama bin Laden, Kerry said he intends to raise the issue with Islamabad, but thought it would be unwise to cut assistance.

"I am not going to recommend, nor do I think it is wise, for American policy to just cut our assistance. We need to build our relationship with the Pakistanis, not diminish it," he said.