As relations between the U.S. and Russia strained after the recent deadly chemical gas attack in Syria, a Russian lawmaker said Moscow will not fight Washington’s troops in Syria, Sputnik reported Monday. In retaliation to the deadly attack, President Donald Trump ordered missile strikes on a Syrian government-controlled air base Thursday — a move that upset Russia.

Victor Ozerov, the head of the Russian Federation Council's defense committee, told Sputnik the Russian Aerospace Forces deployed in Syria are to support President Bashar Assad regime’s anti-terrorism efforts and not engage in military conflict with the U.S.

"Russia is not going there to conduct armed activity with the US, our task there is to support the Syrian armed forces in the fight against terrorism," Ozerov told the Russian news agency, adding, "we have a mandate to fulfill this very task."

Ozerov also maintained that the deployment of Russia’s Admiral Grigorovich-class frigate to the Mediterranean Sea was not connected to the U.S. missile strikes on the Syrian government’s Shayrat air base.

"You cannot deploy such a ship in one day. This rotation is planned; the Admiral Grigorovich escorted the Admiral Kuznetsov [aircraft carrier], and is now back," Ozerov said. "Admiral Grigorovich is quite an effective ship; we have already attacked militants from its deck. Thus, this is not so much about the moral support for the Syrian armed forces in the fight against terrorists, as it is about fire cover."

Last week’s chemical gas attack in Syria killed nearly 100 people and injured dozens. Following this, the U.S. launched 59 Tomahawk cruise missiles targeting the Shayrat air base. While most U.S. allies backed the move, Russia criticized the strikes. There also have been allegations that Moscow may have played a role in the chemical gas attack.

National Security Adviser Lt. Gen. H.R. McMaster said Russia should be pushed to answer whether it knew about the attack beforehand.

“I think what we should do is ask Russia — how could it be, if you have advisors at that airfield, that you didn't know that the Syrian air force was preparing and executing a mass murder attack with chemical weapons? I think we ought to ask them a question,” McMaster said on “Fox News Sunday.”

Secretary of State Rex Tillerson said Russia should reconsider its support to Assad. Moreover, Britain would request Western countries to impose new sanctions on Russia, if Moscow does not end its support to the Syrian president, according to the Sunday Times.