BEIRUT, Lebanon - U.S. President George W. Bush called the Lebanese prime minister on Tuesday and expressed Washington's concern about Lebanon's deadlock over the election of a new president, a government statement said.

Prime Minister Fuad Siniora thanked the American president for the U.S. help to Lebanon, including economic aid and military support to the Lebanese armed forces, according to the statement from the premier's office.

Lebanon is enduring its worst political crisis since the end of the country's 1975-90 civil war. The crisis has pitted the U.S.-supported government against the Syrian-backed opposition, led by the militant Hezbollah group. The country has been without a head of state since pro-Syrian President Emile Lahoud's term ended last November.

In Washington, Bush said at a White House news conference that he called Siniora and described Lebanon as a "struggling democracy in the heart of the Middle East ... whose internal politics are being influenced by Syria, Hezbollah ... all aiming to destabilize the country."

Washington has an ongoing US$60 million program to assist Lebanese security forces.

Meanwhile, U.N. Middle East peace envoy Robert Serry has began a three-day visit to Lebanon. He met Tuesday with Maj. Gen. Claudio Graziano, commander of the U.N. peacekeeping force in southern Lebanon known as UNIFIL, state-run National News Agency said. He is to meet several Lebanese officials during his visit, including Siniora and Parliament Speaker Nabih Berri. -Agencies