Former President Jimmy Carter stopped by the White House Tuesday to greet President Obama and talk foreign policy with the president's national security advisor.

National Security Council spokesman Mike Hammer said Carter and Tom Donilon discussed "the international work of the Carter Center and several foreign policy issues." President Obama also made a brief appearance at the meeting.

With tensions mounting on the Korean peninsula, that region was a likely topic of discussion. Carter, who is considered an expert on the area, recently visited North Korea to help secure the release of an American prisoner.

"I hope that we'll soon have an agreement with North Korea to denuclearize the whole peninsula, and to have...a peacy treaty," Carter told the Associated Press Tuesday at a Washington, DC book signing. "I believe having met with the North Koreans that they're willing to do that on their own terms...but if we can modify their terms with good faith negotiations, maybe we'll have peace and no nuclear weapons on their peninsula."