"With respect to NSA collection of intelligence on leaders of US allies - including France, Spain, Mexico and Germany - let me state unequivocally: I am totally opposed," Senator Dianne Feinstein, chairwoman of the Senate Select Committee on Intelligence said.
"Unless the United States is engaged in hostilities against a country or there is an emergency need for this type of surveillance, I do not believe US should be collecting phone calls or emails of friendly presidents and prime ministers. The president should be required to approve any collection of this sort," Feinstein said.
Feinstein said Congress needs to know exactly what the intelligence community is doing.
"To that end, the committee will initiate a major review into all intelligence collection programmes," she said.
National Security Council spokesperson Caitlin Hayden said the White House consults regularly with Feinstein as a part of its ongoing engagement with the Congress on national security matters.
Earlier, White House Press Secretary Jay Carney, told reporters that Obama feels strongly that the US does not just collect information because it can, but because it should.
"If we're going to keep our citizens and our allies safe, we have to continue to stay ahead of these changes, and that's what our intelligence community has been doing extraordinarily well. These capabilities are part of the reason we've been able to foil numerous terrorist plots and adapt to a post-9/11 security environment," he said.
Meanwhile, the State Department said a German delegation would be coming to the US in the next few weeks to discuss with the US on intelligence gathering and the range of issues related to recent reports in this regard.
