The Washington Post says U.S. President Barack Obama wrote a personal letter to North Korean leader Kim Jong-il that was delivered by the administration's special envoy Stephen Bosworth during a visit to Pyongyang last week.

The article said the existence of the letter has been closely held and the U.S. insisted to its partners in disarmament talks with North Korea that it not be publicly discussed.

The Post said State Department and White House officials confirmed the letter’s delivery this week but declined to describe the letter's content.

The paper said that it is relatively unusual for an American president to send the North Korean dictator a personal communication so early in his term, noting that both Bill Clinton and George W. Bush sent letters to Kim, but only after extensive diplomatic efforts to restrain the North's nuclear ambitions.

The paper said Bosworth had earlier sidestepped questions about a letter from Obama, saying that in effect, he himself was the message.