WASHINGTON, Dec. 5 (Xinhua) -- U.S. President George W. Bush expressed appreciation Friday to Iraqi leaders for their approval of a key security pact which will keep the U.S. military presence in Iraq for another three years.

    "President Bush thanked them for their leadership in securing approval of the Strategic Framework Agreement and the Security Agreement," said U.S. National Security Council spokesman Gordon Johndroe.

    Bush had separate telephone discussions with Iraqi Vice President Adel Abdul Mahdi, Vice President Tariq al-Hashimi, Kurdish leader Massud Barzani, Shiite leader Abdel Aziz al-Hakim and deputy speaker of parliament Khalid al-Attiyah, said Johndroe.

    The Iraqi Presidency Council, comprising President Jalal Talabani, a Kurd, Vice President Adel Abdul Mahdi, a Shiite and Vice President Tariq al-Hashimi, a Sunni, approved on Thursday the controversial security pact with the United States.

    Soon after the approval of the agreement, Bush thanked President Talabani and Prime Minister al-Maliki for their efforts on the deal.

    Under the agreement, U.S. troops will withdraw from Iraq's cities, towns and villages by June 30, 2009 to their bases, and will leave the country on Dec. 31, 2011.

    The agreement also allows Iraq to try U.S. soldiers and contractors for crimes under certain circumstances, most notably when they are off-base or off-duty. It also binds the U.S. not to use Iraq as a base for launching attacks on another country, such as Iran or Syria.

    Currently, there are about 150,000 U.S. troops in Iraq.