efe-epaUnited Nations

Russia blocked on Tuesday a United Nations resolution proposed by the United States to investigate chemical attacks in Syria as the possibility of military action by Washington against the Damascus regime appeared to grow.

Moscow used its veto right in the Security Council to prevent approval of the text of a resolution backed by 12 of the 15 member states of the top UN decision-making body.

According to Russia, the US pushed the initiative merely as a "pretext" to justify possible military action, since it knew that Moscow was not going to accept it.

On Monday, US Ambassador to the UN Nikki Haley had demanded that the Council provide a response to the alleged chemical attack last weekend in Douma and had warned that, if Russia blocked it, Washington was prepared to act alone to make the regime of Bashar al-Assad pay a heavy price for the strike, which reportedly killed at least 42 people.

On Tuesday, after the Russian veto, Haley insisted that the Douma attack cannot go without a response and accused Russia of "trashing" the Council's credibility in its eagerness to defend Assad and his actions against his own people.

"History will record that on this day, Russia chose protecting a monster over the lives of the Syrian people," Haley said.

"Russia has trashed the credibility of the Council," she added.

The US draft resolution would have created an independent international entity to investigate and assign blame for the use of chemical weapons in Syria.

The US and other countries have been insisting on the need to mount an investigation of this kind since last November, when Russia vetoed extending the joint mechanism of the UN and the Organization for the Prohibition of Chemical Weapons that could have accomplished the same thing.

Russia responded on Tuesday to the US proposal by submitting its own initiative to create a new investigative mechanism to a vote, but the Security Council rejected that move.

According to the Western powers, the Russian resolution would not have created an independent investigation and would not have assigned responsibility for the attacks.

Russia had attempted to have the Security Council, where it exercises a veto, decide what experts would participate in the investigation and control the final result of the probe.

According to Haley, however, Moscow's only aim in proposing its initiative was in protecting the Assad regime, and the Council for the second day in a row was the scene of numerous exchanges of accusations between the US - who holds Damascus responsible for the attack - and Russia, who claims that the attack was faked.

A year ago, the US fired almost five dozen cruise missiles at a Syrian army base in reprisal for another chemical attack on civilians that killed about 100 people.