A Japanese newspaper says U.S. President Barack Obama has offered to improve U.S. relations with North Korea if the North reaffirms its commitment to denuclearization.

The Yomiuri Shimbun said Tuesday that special envoy Stephen Bosworth, while on his December visit to North Korea, delivered a personal letter from Obama containing this message to North Korean leader Kim Jong-il.

Quoting several U.S. government officials, the daily said North Korea’s proposal on Monday of peace treaty talks is a response to the message from the U.S. president.

According to Yomiuri, Obama stressed in the letter that it is important for both the U.S. and the North to abide by the September 19th, 2005 Joint Statement, which states that the North would receive economic aid from five other countries in return for scrapping its nuclear program.

The paper said North Korea might have concluded that the U.S. would accept its proposal for peace treaty talks based on the letter from Obama.