President Obama on Monday declined to say if he knew about the National Security Agency’s surveillance of world leaders’ phone calls.

“National security operations, generally, have one purpose and that is to make sure the American people are safe and that I'm making good decisions," Obama said in an interview with Fusion TV. "I'm the final user of all the intelligence that they gather. But they're involved in a whole wide range of issues."

Obama’s comments come after new revelations from NSA leaker Edward Snowden disclosed that the U.S. has been monitoring the phone traffic of dozens of world leaders, including German Chancellor Angela Merkel.

The news sparked anger overseas, with Merkel and Obama speaking by phone about the issue last week.

The White House said Obama reassured the German leader that the U.S. is not monitoring her communications now and will not in the future.

The Obama administration has defended its intelligence programs, saying they have saved lives and thwarted terror attacks, while also vowing to review the NSA’s activities to better balance privacy and security concerns.

Obama said the ongoing review would address the changes in technology which have helped the NSA and other intelligence agencies broaden their surveillance.

"We give them policy direction, but what we've seen over the last several years is their capacities continue to develop and expand, and that's why I'm initiating now a review to make sure that what they're able to do, doesn't necessarily mean what they should be doing," Obama added.

But the latest revelations will bring more scrutiny from Capitol Hill. Senate Intelligence Committee Chairwoman Dianne Feinstein, D-Calif., on Monday said she was unaware of the spying on world leaders, including many U.S. allies and condemned those actions.

“With respect to NSA collection of intelligence on leaders of U.S. allies—including France, Spain, Mexico and Germany—let me state unequivocally: I am totally opposed,” said Feinstein in a statement.

She called a Wall Street Journal report which said Obama was unaware of the spying until an internal investigation this past summer a “big problem.”

Feinstein vowed a “total review of all intelligence programs.”

“Our oversight needs to be strengthened and increased,” she said.

National Security Council spokesperson Caitlin Hayden said that the administration consulted “regularly” with Feinstein, in a statement.

“I’m not going to go into the details of those private discussions, nor am I going to comment on assertions made in the Senator’s statement today about U.S. foreign intelligence activities,” she added.

Hayden said the administration’s review of intelligence practices was “ongoing.”

“We have already made some decisions through this process and expect to make more as we continue,” she said.