The United States has begun an internal review of its military capabilities vis-a-vis Syria despite remaining committed to diplomatic and economic pressure on Damascus, CNN's "Security Clearance" blog reported on Tuesday.The report did not specify whether the White House had ordered the review or if it was initiated in the Pentagon. One senior US official told CNN that the US military "would not be doing its job if it did not put some ideas on the table," adding that "absolutely no decisions have been made on military support for Syria."US Secretary of State Hillary Clinton on Sunday said Washington would work with other nations to try to tighten “regional and national” sanctions “to dry up the sources of funding and the arms shipments that are keeping the regime’s war machine going.“We will work to expose those who are still funding the regime and sending it weapons that are used against defenseless Syrians, including women and children,” she said. “We will work with the friends of a democratic Syria around the world to support the opposition’s peaceful political plans for change.”Clinton did not give further details on which nations might band together, or precisely what they might do, but it appeared that the United States might seek to organize a “Friends of Syria” group to act together given the inability to make progress at the United Nations because of Russia and China.Reuters contributed to this report.Senior officials reiterated to the cable news channel that the US's position remains focused on diplomatic and sanctions-based actions but said the preliminary military planning was being done for the eventuality that US President Barack Obama asked for a military option.Last week, Obama said Syrian President Bashar Assad "must step aside and allow a democratic transition to proceed immediately." In an interview with NBC aired Sunday, the US president put importance on resolving the situation in Syria "without recourse to outside military intervention."