U.S. President George W. Bush has thanked Japan for its help in rebuilding Iraq, saying in a letter to Prime Minister Taro Aso that he was "grateful" for the Self-Defense Forces' assistance, a Foreign Ministry official said.

In the letter, which arrived Wednesday, Bush also said Japan should be proud of its participation in the fight for Iraqi democracy and praised the Japanese people for their "generosity" in providing financial aid to the country.

The president also noted that he remembers and honors the two Japanese diplomats who were killed in Iraq in 2003 by militants, saying their sacrifice "will not be forgotten."

Bush was quoted by the ministry as saying the SDF contributed to the success enjoyed by the Iraqi people and that Japan should be proud of its participation in reducing violence in Iraq.

Japan deployed ground and air forces to Iraq to support reconstruction efforts under a special law enacted in July 2003 on the initiative of then Prime Minister Junichiro Koizumi, who established a close relationship with Bush.

Due to the pacifist nature of the Constitution, Japanese troops were strictly limited to noncombat operations in Iraq, and the security situation there tested the limits of the charter.