The United States on Monday appeared still undecided on the potential imposition of a no-fly zone in Syria as fighting continued to escalate between government forces and rebels across the Middle East country.

"What I can say is that the President and his team have ruled out no options as we try to bring about, with all of our partners, and with the Syrian people, the political transition that is so desperately needed in Syria," said White House spokesman Jay Carney at a press gaggle.

Recently, there is speculation about the possible imposition of a no-fly zone in Syria as the Syrian opposition is raising its voice in calling for such a move. On Sunday after meeting with Turkish Foreign Minister Ahmet Davutoglu in Istanbul, U.S. State Secretary Hillary Clinton gave no definitive answer on the issue, only saying such a decision requires "intense analysis and operational planning."

Without directly responding to the question, Carney said that the Obama administration continued to believe the current approach which involved heavy-handed economic sanctions and international pressure on the Assad regime is the "right course."

"But we review all options, as you would expect, and will continue to do so," he added.

The United States and some other Western countries have been explicit about their demand for Assad to step down and used both diplomatic and economic maneuvers to exert pressure on the Syrian government. Together with some Arab countries, they have also agreed to provide assistance to the Syrian opposition.

However, Russia and China insist any proposed resolution on Syria should be balanced and stipulate binding articles for both the government and opposition. The two UN Security Council permanent members have also opposed any outside military intervention against Syria.