The escalation has drawn decries from the international community that voiced concerns about the deteriorating humanitarian situation and the potential outbreak of a civil war. Some Western countries even said that Syria is already in a state of civil war.
The UN peacekeeping chief Herve Ladsous said Tuesday that the Syrian crisis has grown into a "full-scale civil war."
U.S. Secretary of State Hillary Clinton on Tuesday accused Russia of providing Syria with military helicopters, saying that " the latest information we have (shows) that there are attack helicopters on the way from Russia to Syria."
She said the shipment "will escalate the conflict quite dramatically," and warned that the situation in Syria might get deadlier.
On his part, Russian Foreign Minister Sergei Lavrov denied Clinton's claims and accused the United States of supplying weapons to Syria's rebels.
Russia was supplying "anti-air defense systems" to Damascus in a deal that "in no way violates international laws," Lavrov told a news conference during a brief visit to Iran.
Syria, meanwhile, has rejected any labeling of the ongoing conflict as a civil war, calling it "inconsistent with reality."
"Talk of civil war in Syria is not compatible with reality... What is happening in Syria is a war against armed groups that choose terrorism," Syrian state news agency SANA quoted a foreign ministry statement as saying.
The Syrian government accused the West and the United States of aiding the gunmen, and said it is determined to eradicate " terrorism" and save its own people.
The military showdown was denounced by some parties and individuals in Syria, but observers believe that worries have also dramatically increase among Syrians following reports about the infiltration of al-Qaida-linked Jihadists to fight alongside the Free Syrian Army and the possibility of al-Qaida-style suicide bombings in the country.
As the situation on the ground places obstacles in the way of fully implementing the six-point peace plan proposed by UN-Arab League special envoy Kofi Annan, Syria stressed Wednesday its commitment to the plan, but accused the armed groups of not abiding by it.
Chinese Foreign Minister Yang Jiechi said Wednesday that the international community should fully support Annan's efforts on the Syria issue and adhere to the political path.
Yang reaffirmed China's stance in a telephone conversation with Annan, who briefed Yang about the idea of calling an international conference on the Syria issue and creating a "contact group."
The move, said the envoy, is aimed at implementing related UN Security Council resolutions and facilitating a political solution to the Syria crisis.