U.S. President Barack Obama says he has not yet decided on how to respond to the chemical weapons attack in Syria.
He said the use of chemical weapons affected US national interests and sending a "shot across the bows" could have a positive impact on Syria\’s war.
But in the interview with PBS, said he had not yet made a decision about whether to intervene militarily.
His comments follow a day of behind-the-scenes wrangling at the UN.
The UK had been pushing for permanent members of the UN Security Council to adopt a resolution which would have authorised measures to protect civilians in Syria.
However, Syrian ally Russia refused to agree to the resolution and the meeting produced no end to the diplomatic stalemate which has long characterised the UN position on Syria.
The US State Department criticised "Russian intransigence" and said it could not allow diplomatic paralysis to serve as a shield for the Syrian leadership.
Critics have questioned what purpose a limited strike on Syria could serve, butObama said it would send the government of Bashar al-Assad "a pretty strong signal that it better not do it [use chemical weapons] again".
The US has yet to produce the intelligence it says shows Assad\’s government is guilty of using chemical weapons, and UN weapons inspectors are still investigating inside Syria.
Some lawmakers are calling for Obama to seek congressional approval for a military action.
UN Secretary General Ban Ki-moon has said they need four more days to complete their investigations.
Two days after their convoy was shot at by unidentified snipers, UN arms inspectors resumed their probe into Syria chemical weapons attack on Wednesday.
The inspectors\’ first such visit on Monday was briefly suspended after the UN\’s convoy came under sniper firefrom unidentified gunmen, though they did visit two field hospitals to collect evidence.
Aid agencies say that at least 355 people were killed and more than 3,000 injured in the alleged chemical weapons attack in the Damascus suburb of Ghouta on August 21.
Russian Foreign Minister expressed his opposition to military intervention in a telephone call with U.N.-Arab League peace envoy Lakhdar Brahimi.
Russia\’s Foreign Ministry said Wednesday that Lavrov stressed the need for a political solution, and that the two diplomats agreed all parties inside and outside Syria must act responsibly.
Brahimi has been working for a year to find a peaceful resolution to the crisis.
US Vice President Joe Biden said there is no doubt that Syria\’s government was responsible for a recent chemical attack in Damascus, as Western allies ramp up rhetoric in preparation for possible military strikes against Syria.
The US has not yet released its intelligence report into the alleged chemical attack, but US officials now say they are certain the Syrian government was behind the incident.
Biden is the most senior member of the Obama administration to blame the Syrian government for the attack.
Amid preparations for some form of military strike on Syria, Biden began a speech to the national convention of The American Legion in Texas with tough words for the Assad government.
There is no doubt, he said, that an essential international norm has been violated, and no doubt that the Syrian regime is responsible. And he said the United States and its allies are determined to ensure there is accountability.
"The president believes, and I believe, that those who use chemical weapons against defenseless men, women and children should and must be held accountable," said Biden.
The remarks came as President Barack Obama continues to assess options for a response with key allies.
US forces in the region are “ready to go”, Defence Secretary Chuck Hagel said, as Washington and its European and Middle Eastern partners honed plans to punish Assad for a major poison gas attack last week that killed hundreds of civilians.
The US defence chief said his forces are ready to launch strikes against the Syrian regime over alleged chemical attacks, amid growing Western and Arab calls for action.
Syrian opposition leaders have been told by Western allies to expect military strikes against President Bashar al-Assad\’s government within days, Reuters news agency reports.
According to the report, the Syrian National Coalition was told in clear terms that "action to deter further use of chemical weapons by the Assad regime could come as early as in the next few days". The coalition passed Western allies a list of targets, the report added.
"There is no precise timing… but one can speak of an imminent international intervention against the regime. It\’s a question of days and not weeks," AFP news agency quoted Syrian National Coalition official Ahmad Ramadan as saying.
"There have been meetings between the Coalition, the [rebel] Free Syrian Army and allied countries during which possible targets have been discussed."
American forces are "ready" to launch strikes on Syria if President Barack Obama chooses to order an attack, US Defence Secretary Chuck Hagel says.
"We have moved assets in place to be able to fulfil and comply with whatever option the president wishes to take," Hagel told the BBC.
Syria\’s Foreign Minister Walid al-Moallem is vowing to strike back at any Western military attack with what he calls "surprise" defenses.
Moallem on Tuesday said Syria is hearing war drums. He said the West is using allegations of chemical weapons as an excuse to attack.
He again denied that the Syrian government has used such weapons, and he challenged the United States and its European allies to show evidence.
Because of security concerns Tuesday, United Nations investigators postponed their visit to another Damascus suburb where chemical weapons apparently were used. Snipers fired at a U.N. car during a stop in Moadamiyeh Monday. No one was hurt and the Syrian government and rebels blamed each other for the gunfire.
But it is not just the West condemning Syria. The Arab League meeting in Cairo is blaming the Assad government for the attack and is demanding that those responsible be put on trial.
French President Francois Hollande says his country is ready to punish those who made the "vile" decision to gas innocent people. He also promised France will increase its military support to the main Syrian opposition group.
Israeli Prime Minister Benjamin Netanyahu warned of a "forceful" response if Syria makes any attempt to attack Israel.
Turkish Foreign Minister Ahmet Davutoglu denounced the Syrian government\’s alleged chemical weapon attacks near Damascus as a "crime against humanity" and said it must "not go unanswered."
But China\’s state news agency Xinhua cautioned against a rush to military action. In a Tuesday commentary, it said the world should remember that the 2003 U.S.-led invasion of Iraq followed U.S. allegations that Iraqi dictator Saddam Hussein had weapons of mass destruction. Those weapons were never found.
Syria has been embroiled in a war for more than two years, during which more than 100,000 people have been killed and millions have been displaced or become refugees in other countries, according to the United Nations.