MOSCOW (AFP, REUTERS) - Moscow considers the US strike on a Syrian airbase early Friday (April 7) as "aggression against a sovereign state", which will further harm US-Russia ties, Kremlin spokesman Dmitry Peskov said.

Moscow also announced it was halting an agreement with the United States aimed at avoiding clashes between their forces in the skies over Syria in response to Washington's strike in the war-torn country.

"President Putin considers American strikes on Syria aggression against a sovereign state in violation of international norms, and under an invented pretext," Peskov was reported as saying by Russian agencies.

US President Donald Trump ordered a massive military strike on a Syrian air base at 0040GMT (8:40am Friday Singapore time), in retaliation for what he described as a "very barbaric" chemical gas attack on Tuesday that left scores dead in the Syrian province of Idlib.

"The Syrian army does not have any chemical weapon stockpiles," added Peskov.

"The fact of destruction of all chemical weapon stockpiles of the Syrian armed forces was recorded and confirmed by the (Organisation for the Prohibition of Chemical Weapons)."

"This step by Washington inflicts considerable damage to US-Russia relations, which are already in a lamentable state," Peskov added.

A White House official said 59 precision-guided Tomahawk missiles hit the Shayrat airfield, from where the US believes the attack was launched. Syria said the base was nearly destroyed with six soldiers killed.

Russia wants an emergency meeting of the UN Security Council to discuss the strikes, the Russian Foreign Ministry said on Friday.

The ministry said in a statement that Russia was also suspending a Syrian air safety agreement with the United States, saying: "This is not the first time the United States has resorted to such a thoughtless step, which merely exacerbates existing problems and threatens global security."

Russia has dismissed Western accusations against Syrian President Bashar al-Assad who Washington says was responsible Tuesday's chemical gas attack. The foreign ministry said it was clear that the US missile strikes were prepared before the Idlib incident.

The strikes, however, are unlikely to halt US Secretary of state Rex Tillerson's planned visit to Moscow next week, the head of the Russian lower house of parliament's international affairs committee said on Friday.

"I don't think this will impact Tillerson's visit, we need to restore dialogue. We should welcome Tillerson, exchange views and try and talk sense into Washington," Leonid Slutsky told the Russia 24 television channel, Interfax reported.

"That's much better than hiding behind walls." Tillerson is due to visit Russia for talks next week.

The United States on Friday fired dozens of cruise missiles at a Syrian air base from which it said a deadly chemical weapons attack was launched this week. Russian President Vladimir Putin has called the action "aggression against a sovereign nation" on a "made-up pretext".