Washington, Nov 24: French President Francois Hollande arrived in Washington on Tuesday seeking support for his newly declared war on the Islamic State group, while the US announced a worldwide travel alert for its citizens.
As Hollande prepared for talks with President Barack Obama on the campaign against IS in Syria and Iraq, the manhunt continued in Europe for Belgian-born Salah Abdeslam, a key suspect in the Paris attacks that killed 130 people.
As Brussels entered a fourth day of lockdown over fears of an "imminent" attack, relations between Russia and Turkey -- two countries seen as key to resolving the Syria conflict -- were plunged into crisis by Turkey's downing of a Russian warplane.
Meanwhile, police in France said they were analysing what is thought to be a suicide belt similar to those used in the Paris attacks, found without its detonator in a dustbin in the Montrouge suburb of the capital.
Telephone data placed Abdeslam in the area on November 13, the night of the attacks.
Brussels will stay on its highest level of alert at least until next Monday, with Belgian Prime Minister Charles Michel warning that the threat "remains serious and imminent", though schools and the Metro train system will re-open Wednesday.
The security measures include city-wide patrols of armed soldiers and police, not seen in Brussels for two decades.
Belgian authorities have charged a fourth person in connection with the bloodshed in Paris, which was claimed by the Islamic State group.
The delicate diplomacy around the Syrian conflict ran into further trouble after Russia confirmed one of its fighter jets had been shot down by Turkey at the Syrian border.
Washington and Paris have stepped up their fight against IS in Syria, with France launching its first strikes from the Charles de Gaulle aircraft carrier in the Mediterranean on Monday and the US calling for more international cooperation against the jihadist group.