U.S. mulls humanitarian aid, not arms, for Syrian rebels Updated 3:47 PM ET WASHINGTON - The White House says the U.S. is not considering arming opposition groups in Syria amid calls from some lawmakers to consider such an option. Spokesman Jay Carney says that at this point, U.S. efforts are focused on exploring the possibility of providing humanitarian aid to the Syrian people. And he says the U.S. continues to look for ways to ratchet up the pressure on the Syrian government. Carney says pressure on President Bashar Assad's regime is having an impact. But he says that pressure must ultimately result in Assad stopping the violence in Syria and leaving power. Earlier Tuesday, some lawmakers, including Arizona's Republican Sen. John McCain, called for the U.S. to considering arming the opposition in Syria. "We should start considering options, arming the opposition," McCain said. The bloodletting has got to stop. More than 5,400 people have been killed in Syria since the uprising began in March, according to a United Nations count from early last month. The U.S. has been loath to consider any type of military intervention in Syria, preferring sanctions instead. The White House and its allies had also hoped to push through a resolution at the U.N. Security Council calling for Assad to leave power, but the measure was vetoed Saturday by both Russia and China, leaving the U.S. searching for its next step. Carney defended the actions the U.S. and its allies have taken thus far, saying the pressure on the Assad regime is working. "Ultimately it needs to result in Assad ceasing the violence, stopping the brutality and allowing for a transition supported by the Syrian people," he said. U.S. closes Syria Embassy, pulls all staff Russia's Lavrov visits Syria, urges reform Syrian resistance worried about regime air power Meanwhile, Russian Foreigner Minister Sergey Lavrov Russia's foreign minister urged Syrian President Bashar Assad to move ahead with reforms Tuesday as a way to resolve Syria's crisis, as a cheering crowd of thousands waving Russian flags welcomed the diplomat, praising his country for blocking U.N. pressure on Damascus. Syria's opposition has dismissed Assad's promises of reform as empty gestures to play for time as he tries to crush the nearly 11-month uprising against his rule. On Tuesday, regime troops renewed their assault on one of the main centers of the opposition, the city of Homs, with activists saying tanks were closing in on one of its most restive neighborhoods. Activists said at least 15 people were killed in violence Tuesday around the country.