Russia has demanded that American warplanes exit Syrian airspace immediately, a US official told Fox News on Wednesday. The official said that Russian diplomats sent an official message to the US ordering American planes out of Syria, adding that Russian fighter jets were now flying over Syrian territory, according to the report. US military sources told the news outlet that US planes would not comply with the Russian demand. "There is nothing to indicate that we are changing operations over Syria," a senior defense official told Fox. The Russian parliament on Wednesday unanimously granted President Vladimir Putin the right to deploy the country's military in Syria, a move a top Kremlin aide said related only to the air force.Russia has been building up its military presence in Syria, where it supports the government forces of President Bashar Assad in a conflict that pits him against Islamic State militants and Western-backed rebels.Sergei Ivanov, the head of the Kremlin administration, said after the vote in the Federation Council, the Russian parliament's upper chamber: "The Syrian president asked the leadership of our country for military assistance."But he said the vote did not mean that Russian ground forces would be engaged in conflict and that the move referred to the use of the air force only. On Sunday the US-led coalition launched 23 air strikes against Islamic State militants in Syria and Iraq.