Ankara: Turkey will launch a "new initiative" with like-minded countries after the rejection of a UN resolution aimed at ending months-long bloodshed in neighbouring Syria, its prime minister said on Tuesday.

"We will start a new initiative with those countries who stand by the Syrian people, not the regime," Prime Minister Recep Tayyip Erdogan said in parliament, without elaborating.

Erdogan's announcement came after the United States proposed an international coalition to support Syria's opposition after Russia and China on Saturday blocked a UN attempt to end nearly 11 months of bloodshed.

The commander of the Free Syrian Army said that after the vetoes at the UN, "there is no other road" except military action to topple Syrian President Bashar Al Assad.

"We consider that Syria is occupied by a criminal gang and we must liberate the country from this gang," Colonel Riad Al Asaad said, speaking by telephone from Turkey. "This regime does not understand the language of politics. It only understands the language of force."

US Secretary of State Hillary Rodham Clinton warned that chances for "a brutal civil war" would increase as Syrians under attack from their government move to defend themselves, unless international steps provide another way.

Speaking to reporters in the Bulgarian capital of Sofia, she called the double veto at the UN Security Council on Saturday "a travesty."

"Faced with a neutered Security Council, we have to redouble our efforts outside of the United Nations," she said, calling for "friends of democratic Syria" to unite "support the Syrian people's right to have a better future."