U.S. President Donald Trump confirmed Wednesday that CIA chief Mike Pompeo had held clandestine talks with North Korea's Kim Jong Un, as the two nations move closer to a landmark summit that would see their sitting leaders meet for first time ever.

The meeting came amid a flurry of diplomatic activity involving the U.S., Japan, China and the two Koreas, including news that Seoul was examining the prospect of replacing the armistice that ended fighting in the Korean War with a peace regime.

The seemingly daily onslaught of developments on the Korean Peninsula have raised hopes of a breakthrough in persuading Pyongyang to rein in its nuclear and missile programs at the Kim-Trump summit due to be held by June and before that at a meeting between Kim and South Korean President Moon Jae-in on April 27.