Fran?ois Hollande will urge Barack Obama to intensify the military campaign against Isis when he visits the White House tomorrow, as the French president steps up his diplomatic offensive in the wake of the Paris attacks.

Mr Hollande plans to push for a “sense of urgency” in Syria as part of a week of frantic consultations spearheaded by France to mount what Mr Hollande has called a “grand coalition” against the Islamist militants.

The Paris atrocities that killed 130 people more than a week ago continued to spread alarm across Europe, with Brussels on a security lockdown all weekend. Belgium is keeping its metro and schools closed today in the capital city because of a “serious and imminent” threat of co-ordinated, multiple attacks, said Charles Michel, the Belgian prime minister.