On 7 April, in response to chemical weapon attacks (most notably the Khan Shaykhun chemical attack) against Syrian civilians allegedly by the Syrian government, the U.S. launched missile strikes on the airfield from which the chemical weapon attacks were allegedly launched. This incident marked the first deliberate direct attack by the U.S. on the Assad government. The Russian Foreign Ministry denounced the attack as being based on false intelligence and against international law, suspended the Memorandum of Understanding on Prevention of Flight Safety Incidents that had been signed with the U.S., and called an emergency meeting of the UN Security Council.