Ellen Sauerbrey, the U.S. assistant secretary of state for population, refugees and migration, is the most senior American official to visit Syria since the U.S. withdrew its ambassador following the 2005 assassination of former Lebanese Prime Minister Rafik Hariri.

U.S. officials rarely visit Syria, although Washington has said in recent months it wants to reach out to Damascus over the fate of the estimated 1.5 million Iraqi refugees that have sought sanctuary in Syria since the beginning of the Iraq war.

State Department spokesman Sean McCormack stressed that Sauerbrey's trip was not a "bilateral mission," saying she was accompanying the U.N. High Commissioner for Refugees on a humanitarian visit to discuss the refugee crisis.

Her visit, however, comes days after an international conference was held in Baghdad bringing together Syrian, Iranian and U.S. officials to discuss security in Iraq.

Syria has frequently called for dialogue with the U.S., but President Bush had previously rejected any direct talks with officials from Syria and Iran, accusing both of them of supporting an influx of foreign fighters into Iraq. Both countries have repeatedly denied the charges.

U.S.-Syrian relations have also been strained in recent years because of Damascus' support for Palestinian militant groups and the Lebanese Hezbollah. The U.S. withdrew its ambassador from Syria to protest Hariri's assassination, which many Lebanese blame on Damascus. Syria has denied being involved.

Syrian Deputy Foreign Minister Fayssal Mekdad told reporters following a one-hour meeting with Sauerbrey that none of the region's problems will be solved without dialogue and cooperation.

"All the issues in the Arab world are related to each other and it is necessary to have comprehensive dialogue on all these issues," he said.

Sauerbrey refused to make any comments following the meeting. In Washington, State Department deputy spokesman Tom Casey said she had called on Syria to work with the Iraqi government, as well as with the UNHCR, to provide protection and assistance for Iraqi refugees.

In response, Syria expressed a willingness to continue hosting the displaced Iraqis while also noting the challenges it poses for the government, Casey said. Sauerbrey met alone with the Syrians because a UNHCR official who was supposed to have attended could not be present, he said.

Last month, the Damascus office of the UNHCR said about 40,000 new Iraqis arrive in Syria each month, almost double the rate from only a few months ago. The refugees have placed a strain on Syria, causing a rise in the prices of housing and goods and overcrowding the country's schools.

The Interior Ministry said in December that Syria has admitted more than 800,000 Iraqis fleeing the raging violence in their country. Unofficial statistics have put the number at about 1.5 million refugees.