US President Barack Obama is keeping all options on the table to help the Syrian opposition in its battle to oust the regime of Bashar al-Assad, including the possibility of implementing a no-fly zone, Obama's Chief Counterterrorism Adviser John Brennan said Wednesday. Brennan said the administration already is providing support in various ways to the rebels, including humanitarian aid. Speaking at the Council on Foreign Relations in Washington, Brennan said the United States is looking at scenarios and making contingency plans as the situation evolves in Syria. "These are things that the United States government has been looking at very carefully, trying to understand the implications, trying to understand the advantages and disadvantages of this, and the president has kept us all quite busy making sure that we're able to do everything possible that's going to advance the interests of peace in Syria and not again going to do anything that is going to contribute to more violence," Brennan said. When asked if a no-fly zone was on the table of options, Brennan responded, "I don't recall the president ever saying that anything was off the table." According to the (CNN), Brennan is worried about al Qaeda taking advantage of the chaos in Syria to establish a presence as it has done in Iraq, Yemen and Somalia. But he is encouraged that the Syrians seem to be resisting the extremism. "The Syrian oppositionists have come out and have said that they're very concerned about the al Qaeda types and they have said that they are not going to sort of allow al Qaeda to take advantage of the situation there," said Brennan.