Russia has warned the US that unilateral attacks on Syria will play into the hands of Isis and other extremist groups.

The message was delivered in a call between Russian Foreign Minister Sergei Lavrov and US Secretary of State Rex Tillerson in what was their first conversation since two American warships struck the Syrian airbase of Shayrat.

Washington said the base was used by the Syrian government to launch a chemical weapon attack in Khan Sheikhoun, but Syria has denied playing any role in the attack.

The retaliatory strike was said to be a deterrent for future attacks, but Lavrov told Tillerson such attacks threaten international security.

"Lavrov underscored that an attack on the country which government battles terrorism merely plays into the hands of extremists and creates additional threats for regional and global security," a Russian foreign ministry spokesman said in a statement.

Lavrov is also said to have repeated Russia's position that the Syrian government did not carry out any chemical weapons attacks and stressed the importance of an independent investigation.

"[The foreign minister] emphasised that facts should be established in a thorough, impartial and professional manner in relation to that incident," the statement continued.

Similar calls for an investigation have been made by Scotland, China, Iran and Bolivia.

The two foreign ministers are due to meet in Moscow this week where they will continue their conversation about the attack and the wider situation in Syria.

Appearing on ABC's This Week, Tillerson said the missile strike on Syria did not reflect a change of policy towards the country.

"I think the president was very clear in his message to the American people that this strike was related solely to the most recent, horrific use of chemical weapons," he said.

Britain's foreign secretary, Boris Johnson, was due to attend the meeting with Lavrov and Tillerson but issued a statement on Saturday (8 April) announcing his intention to withdraw.

Russia's Foreign Secretary Sergei Lavrov and US Secretary of State Rex Tillerson discussed the missile strike on Syria on 7 April, 2017. Reuters