WASHINGTON - Syrian President Bashar Assad has fired missiles with chemical weapons at his opponents, crossing US President Barack Obama's red line a "long time ago," Turkish Prime Minister Recep Tayyip Erdogan was quoted as telling NBC News on Thursday."It is clear that the regime has used chemical weapons and missiles. They used about 200 missiles, according to our intelligence," Erdogan said in a transcript of the interview with the American television news outlet in Istanbul.The Turkish leader did not make clear whether Turkey believed that all 200 missiles carried chemical weapons and said his government had not determined whether sarin gas was used."There are different sizes missiles. And then there are deaths caused by these missiles. And there are burns, you know, serious burns and chemical reactions," Erdogan told the network when asked what evidence Turkey had."And there are patients who are brought to our hospitals who were wounded by these chemical weapons," he added."You can see who is affected by chemical missiles by their burns," said Erdogan, who told NBC Turkey would share intelligence with the United Nations Security Council.Washington has long said it views the use of chemical weapons in Syria as a "red line." But, wary of the false intelligence that was used to justify the 2003 war in Iraq, the United States says it wants proof before taking any action.Asked if Assad had crossed that line, Erdogan said: "Long time ago."Assad's forces and opposing rebels have accused each other of using chemical weapons. Erdogan told NBC he rejected the idea that Assad's opponents has used such weapons because they lacked access to them.Turkey's state-run Anatolian news agency said earlier on Thursday that the country has sent a team of eight experts to the border with Syria to test wounded victims of the country's civil war for traces of chemical and biological weapons.