President Obama has said a video appearing to show the murder of a Jordanian pilot by Islamic State is another indication of the "viciousness and barbarity" of the organisation.
"Should this video be authentic, it's just one more indication of the viciousness and barbarity of this organisation," the president told reporters.
"It will redouble the determination on the part of the global coalition to make sure they are degraded and ultimately defeated.
"Whatever ideology they're operating off of, it's bankrupt."
More top news
Your morning briefing to all the key election news and our latest expert analysis.
Ms Rayner and the Labour leader will visit Blackpool on Tuesday to outline their proposals.
The far south and the northwest of England will be driest.