Valerie Amos arrived in Damascus earlier on Wednesday and met the foreign minister before departing for Homs, said a U.N. spokesman in Syria, Khalid al-Masry. The government had rebuffed an earlier request by Amos to visit the country this month as regime troops attacked the Baba Amr neighborhood in Homs, finally wresting it back from rebels last Thursday.
Despite international appeals, the Syrian government still has not allowed any aid workers into Baba Amr, saying there was a security risk. But activists say the government has been engaged in a "mopping-up" operation to hide their activities. Al-Masry said he did not know if Amos would visit Baba Amr.
Amos has said the aim of her visit is "to urge all sides to allow unhindered access for humanitarian relief workers so they can evacuate the wounded and deliver essential supplies." The trip comes as Syrian President Bashar Assad defies mounting international pressure to end the year-old crackdown on an uprising against him.
According to state news agency SANA, Assad said Tuesday that he will continue to confront "foreign-backed terrorism." Since the uprising began last March, he has blamed armed gangs and foreign terrorists for the unrest, not protesters seeking change.
The U.N. says more than 7,500 people have been killed since Syria's uprising began. Activists put the death toll at more than 8,000.
Despite the growing bloodshed, President Barack Obama said Tuesday that unilateral U.S. military action against Assad's regime would be a mistake. The United States said it is proposing a new United Nations Security Council resolution demanding an end to violence in Syria, first by government forces and then by opposition fighters. Russia and China, powerful Syrian allies that have blocked a Security Council resolution against Syria, have made clear they were still standing by the regime in Damascus.
Still, in a sign of China's growing alarm, Chinese Commerce Minister Chen Deming said Beijing was pulling its workers out of Syria because of the violence. "I can tell you most Chinese workers have been withdrawn from that country to China," he told a news conference Wednesday. "There are only about 100 people left there taking care of projects, assets and property. We will wait until the local situation stabilizes. We will go back to Syria and restart those projects."
Obama has resisted calls to step into the turmoil in Syria to stop Assad's bloody crackdown on protesters. He told a news conference Tuesday that the international community has not been able to muster a campaign against Syria like the one in Libya that ousted Gadhafi last year.
"For us to take military action unilaterally, as some have suggested, or to think that somehow there is some simple solution, I think is a mistake," Obama said. "What happened in Libya was we mobilized the international community, had a U.N. Security Council mandate, had the full cooperation of the region, Arab states, and we knew that we could execute very effectively in a relatively short period of time. This is a much more complicated situation."
Obama's strategy has been to use sanctions and international diplomatic isolation to pressure Assad into handing over power.
The top U.S. commander in the Middle East said the advanced air defense weapons Russia has provided to Syria would make it difficult to establish a no-fly zone there as part of an effort to help the rebellion. Marine Gen. James Mattis, head of U.S. Central Command, told the Senate Armed Services Committee it would take a significant military commitment even to create safe havens in Syria where aid could be delivered.