U.S. President Barack Obama convened a meeting of his national security team on Saturday to review options of responding to the alleged use of chemical weapons in Syria.

Obama and his military and security aides met at the White House to assess the latest intelligence concerning the alleged chemical attack by Syrian government troops last Wednesday, and discuss the options of a U.S. response, the White House said in a statement.

"The U.S. intelligence community continues to gather facts to ascertain what occurred," it said. "The President also received a detailed review of a range of potential options he had requested be prepared for the United States and the international community to respond to the use of chemical weapons."

The statement did not give further details of the meeting, in an indication that no decision has been made on possible U.S. military intervention in Syria.

White House officials have said the United States has a range of options available, and will act "very deliberately" so as to make decisions consistent with U.S. national interests and assessment of how to advance its objectives in Syria.

In an interview with the U.S. cable TV network CNN broadcast Friday, Obama said U.S. officials were "right now gathering information" on "what we've seen indicates that this is clearly a big event of grave concern."

He said the United States was pushing "to prompt better action" from the United Nations, and calling on the Syrian government to allow an investigation of the site of the alleged attack outside Damascus.

But he was cautious on whether to intervene militarily in Syria, saying "if the U.S. goes in and attacks another country without a UN mandate and without clear evidence that can be presented, then there are questions in terms of whether international law supports it."

Obama previously declared the use of chemical weapons as crossing "a red line" by the Syrian government that could lead to U.S. direct intervention. But he has failed to take major actions after the reported use of chemical weapons in Syria in March.

U.S. Defense Secretary Chuck Hagel, who is on a tour in Southeastern Asia, told reporters Friday that Obama has asked the Defense Department for options of responding to the Syrian use of chemical weapons.

"Like always, the Defense Department is prepared, has been prepared to provide options, ranges from all contingencies to the president of the United States. We'll continue to do that," Hagel said in his briefing to reporters aboard his plane.

Hagel said the options the Pentagon has provided require " positioning our forces, positioning our assets to be able to carry out different options, whatever options the president might choose. "

But he declined to reveal details about ongoing deployment of U. S. troops in the Middle East in preparation for a possible military response to Syria.

The Pentagon, the State Department and the intelligence agencies met Friday for three and a half hours at the White House to deliberate over options, which officials say could range from a cruise missile strike to a more sustained air campaign against Syria.

As part of the U.S. military preparation, media reports on Saturday quoted unidentified defense officials as saying that the U.S. Navy had sent a fourth warship, which is armed with cruise missiles, into the eastern Mediterranean Sea.