The United States Thursday welcomed apparent progress in Europe toward fielding an upgraded U.N. peacekeeping force for Lebanon. At the same time, the State Department condemned as "preposterous" Syria's stand that the U.N. force should not be allowed to patrol its border with Lebanon.

Syria's Foreign Minister Walid Mualem

Officials here view deployment of the upgraded U.N. force as critical to preventing another outbreak of hostilities between Israel and Hezbollah, and to getting more humanitarian relief supplies into southern Lebanon.

As such they are welcoming the French decision to commit 2,000 troops to the envisaged 15,000-member force, and saying the United States would support either France or Italy to command the expanded version of the U.N. force in southern Lebanon, UNIFIL.

The French initially signaled a readiness to take the lead of the new UNIFIL, but hesitated last week and said they would commit a total of only 400 soldiers.

However, Thursday French President Jacques Chirac said he was ordering 1,600 additional troops to take part, drawing an expression of relief from the White House, which said President Bush welcomes the French decision.

European Union foreign ministers are to meet with U.N. Secretary-General Kofi Annan Friday in Brussels to discuss additional troop commitments and define rules of engagement for the force.

At a news briefing, State Department Acting Spokesman Gonzalo Gallegos said the United States wants a "robust" force that will facilitate withdrawal of Israeli troops from southern Lebanon, and help fulfill other provisions of the August 12 Security Council resolution ending the fighting between Israel and Hezbollah.

Those, he said, include blocking the transfer of all weapons into Lebanon except those approved by the Beirut government. In that regard, he condemned a statement Wednesday by Syrian President Bashar al-Assad that he would not accept a UNIFIL presence along his country's border with Lebanon.

The United States has long held that Syria has allowed its territory to be used for trans-shipment of Iranian arms to Hezbollah, and spokesman Gallegos said Syria, as a matter of international law, must obey the U.N. arms ban:

"It is a singular duty for Syria, as the one country apart from Israel that borders Lebanon, to do so," he said. "The Syrian suggestion that UNIFIL forces assisting the government of Lebanon to secure its borders will somehow be a hostile act, or a threat to Syria, is preposterous. We call on the Syrian regime to fulfill its international obligations and respect and abide by U.N. Security Council resolutions that reflect the unanimous consensus of the international community."

The Syrian President told Dubai television the presence of U.N. troops on the Lebanese side of the border would create what he termed "a state of hostility" between Syria and Lebanon.

Other Syrian officials have warned that if the envisaged deployment occurs, Syria would seal off the border with Lebanon, severing a critical economic lifeline for the country as it struggles to recover from more than a month of warfare.

Spokesman Gallegos said Secretary of State Condoleezza Rice discussed the situation by telephone Thursday with Lebanese Speaker of Parliament Nabih Berri, a leading Shi'ite politician who has been a go-between with Hezbollah.

The secretary also had a conversation late Wednesday with Israeli Prime Minister Ehud Olmert.

His office said he told Rice it is important that the U.N. resolution be implemented fully for the ceasefire to be preserved. Mr. Olmert was also quoted as saying a quick deployment of the force will allow Israel to remove its air and naval blockades on Lebanon.