Washington, Jun 14 (IANS/RIA Novosti): US Secretary of State Hillary Clinton has warned Russia that its support for the regime of Syrian President Bashar al-Assad will have negative consequences.

"The situation is spiralling towards civil war, and it's now time for everyone in the international community, including Russia and all Security Council members, to speak to Assad with a unified voice and insist that the violence stop, and come together with Kofi Annan to plan a political transition going forward," Clinton said Wednesday at a joint press conference with Indian Foreign Minister S.M. Krishna.

"It is something that we believe is in everyone's interests, most particularly the Syrian people. And Russia says it wants peace and stability restored. It says it has no particular love lost for Assad. And it also claims to have vital interests in the region and relationships that it wants to continue to keep. They put all of that at risk if they do not move more constructively right now," she said.

According to UN estimates, over 10,000 people, mostly civilians, have been killed in Syria and thousands displaced since the uprising against Assad began about 15 months ago.

Russia - along with China - has twice vetoed UN resolutions against Damascus over what it says is a pro-rebel bias. Moscow has, however, fully backed UN and Arab League special envoy Kofi Annan's peace plan for Syria.

Clinton also urged Russia to stop arms deliveries to Syria.

"We have repeatedly urged the Russian government to cut these military ties completely and to suspend all further support and deliveries," she said.

Clinton earlier said Russia was supplying attack helicopters to Syria, but Russian Foreign Minister Sergei Lavrov dismissed the claims, saying Russia was "completing the implementation of contracts that were signed and paid for a long time ago".

He said the contracts "concern exclusively anti-aircraft defence".

Syria is one of Russia's major weapons clients, and Moscow has opposed proposals for an arms embargo on Damascus, saying this would give rebel forces an unfair advantage in the conflict.

Lavrov said Russia does not supply to Syria or other countries any special equipment that may be used against peaceful demonstrators, adding that the US, on the contrary, "delivers riot control equipment to the region".

Clinton has dismissed claims that the US has armed the Syrian opposition.

"I would emphasize that the US has provided no military support to the Syrian opposition, none. All of our support has been medical and humanitarian to help relieve the suffering of the Syrian people, a total of $52 million so far. We have also provided non-lethal support to the opposition, including things like communications gear," she said.