NATO is set to join the US-led coalition against Daesh, diplomatic sources say.
In a show of "unity", following the Manchester suicide attack claimed by Daesh, member states of the military alliance are expected to formally join a US-led coalition in Iraq and Syria.
The decision by the North Atlantic Council, the highest decision-making body within NATO, is expected to be officially announced at a meeting today.
One diplomatic source reported by Al Jazeera said: "The NATO [member state] ambassadors decided this evening an action plan on terrorism for the summit. It includes the accession of NATO to the global coalition against IS [Daesh]."
With many of the 28 member states already taking part individually as part of the coalition, the decision to join is said to be mainly political.
Diplomats said France and Germany will agree to the US plan, but insist the move is purely symbolic.
"NATO as an institution will join the coalition," one senior diplomat involved in the discussions told the Reuters news agency. "The question is whether this is just a symbolic gesture to the United States. France and Germany believe it is."
Earlier yesterday, US Secretary of State Rex Tillerson said he expected NATO to join despite reservations by some members states which are fearful of getting dragged into another conflict.
Tillerson said that NATO's joining "would be a really important step" but that "there are a couple of countries that are still thinking it over."
"I have had meetings actually with one of those. I think they're going to support NATO joining and becoming a member of the ISIS [Daesh] fight," he told reporters travelling with Trump.
NATO chief Jens Stoltenberg said earlier that "many allies would like to see NATO as a full member of the coalition … because it sends a strong message of unity".
He added that in light of Monday's attack in Manchester, "it is important to send this message of unity against terrorism".
Stoltenberg had previously stressed that there has been "no discussion at all of engaging NATO in a combat role" if it officially joins the coalition.