The US and its Western allies should be careful not to "overplay its hand" on the future of Syrian President Bashar al-Assad, Crispin Blunt said on Monday (10 March).

The Conservative chair of the House of Commons' Foreign Affairs Committee issued the warning after the US and UK blamed Assad's forces for chemical attack on Khan Shaykhun on 4 April.

The gassing, which left at 87 people dead, led to Donald Trump ordering a missile strike on Shayrat airbase and British Foreign Secretary Boris Johnson pulling out of a planned meeting with Russian Foreign Minister Sergey Lavrov.

Johnson will now travel to a G7 summit in Italy where he will urge the leaders to push for Russia to pull its soldiers out of Syria.

"The publicly available evidence certainly supports Defence Secretary Michael Fallon's position and presumably he has had sight of further confirmatory classified data," Blunt told IBTimes UK.

"The Russian failure to deliver the 2013 deal would make them either complicit or betrayed by their Syrian ally. In the circumstances the Foreign Secretary's decision to postpone any Moscow visit whilst working to secure G7 support for US Secretary of State [Rex] Tillerson's mission to Moscow seems a sensible judgement.

"The key issues remain getting the political process back on track and the defeat of [the so-called Islamic State] Isis.

"The coalition should be careful not to overplay its hand in respect of the future of Assad, and should rest on the ISSG [International Syria Support Group] agreement of November 2015 that his fate is a matter for the Syrian people in a properly-overseen election that includes those displaced by the conflict."

The US administration has sent mixed messages over its Assad position, with UN diplomat Nikki Haley telling CNN "regime change is something that we think is going to happen because all of the parties are going to see that Assad is not the leader that needs to be taking place for Syria."

Tillerson, in contrast, pointed to the West's intervention in Libya and told ABC that "we have to learn the lessons of the past". For his part, Johnson has been branded "Washington's poodle" by Liberal Democrat leader Tim Farron for pulling out of his Moscow trip.