Less than a year after he called NATO "obsolete," U.S. President Donald Trump heads to the alliance's new billion-dollar, state-of-the-art headquarters for a May 25 meeting that members hope will show it is more relevant than ever.
Talk at the meeting is expected to focus on two main themes: getting all 28 NATO members to reach mandated spending targets and how to combat terrorism against the backdrop of the May 22 bombing in Manchester, England, that killed 22 people.
U.S. Secretary of State Rex Tillerson told reporters aboard Air Force One as it flew toward Brussels on May 24 that Trump, on his first foreign trip since taking office in January, wants NATO members "to step up and fully meet their obligations" of spending 2 percent of gross domestic product on defense.
"I think you can expect the president to be very tough on them, saying: 'Look, the U.S. is spending 4 percent. We're doing a lot. The American people are doing a lot for your security, for our joint security. You need to make sure you're doing your share for your own security as well,'" Tillerson said.
"So I think that's going to be the core of his message to NATO," he said.
Trump called NATO "obsolete" during the U.S. presidential campaign last year, saying it was not doing enough to fight terrorism, while he chided members for slow progress toward meeting NATO guidelines on spending.
Only the United States, Britain, Poland, Estonia, and Greece met the NATO spending target last year while Latvia, Lithuania, and Romania came close to the target. Washington funds about 70 percent of NATO spending, and all members share the costs of running the alliance's day-to-day administration and building costs.
'No Longer Absolute'
But the president has recently softened his criticism. In April, he said NATO is "no longer obsolete" after many allies -- following repeated exhortations by senior U.S. officials earlier this year -- started making plans to increase their military spending and incorporate antiterrorism into NATO's mission.
Tillerson said the United States would like to see NATO become more engaged in the fight against terrorism by becoming a full member of the 68-nation U.S.-led Global Coalition whose goal is to defeat Islamic State (IS).
NATO Secretary-General Jens Stoltenberg said the "brutal" bombing in Manchester on May 22 shows that the alliance must agree at the meeting to do more to combat terrorism.
The extremist group IS claimed responsibility for the May 22 attack, in which a suspected suicide bomber set off explosives as concertgoers were leaving Manchester Arena after watching American pop singer Ariana Grande perform.
The blast killed 22 people and injured about 60 others. Many of the victims were children, including an 8-year-old girl who was among the dead.
“We are still discussing whether NATO should become a full member of the Global Coalition," Stoltenberg said.
Diplomats from NATO nations have told RFE/RL that the alliance is expected to formally join the coalition.
Twenty-three of the Global Coalition’s partners have over 9,000 troops in Iraq and Syria in support of the effort to defeat IS, while its air assets have conducted more than 19,000 strikes on IS targets.
All 28 NATO allies have joined the coalition as individual countries, but Stoltenberg said that, if the alliance became a member, it would significantly boost coordination in the war against IS.
It would also send "a strong message of unity...and especially in light of the attack in Manchester, I think it is important to send this message of unity against terrorism," Stoltenberg said.
"Many allies would like to see NATO as a full member of the coalition," he said.
Turkish President Recep Tayyip Erdogan said on May 24 that the Manchester bombing showed terrorism was a global problem and that NATO allies should cooperate more closely and share information swiftly to confront it.
In addition to slamming NATO during the U.S. election campaign, Trump also took aim at the city that is now hosting him, calling Brussels a "hellhole," citing a lack of "assimilation" by Muslims living there.
On May 24, hundreds gathered at a Brussels trains station with banners and placards denouncing Trump as a sexist and a racist and accusing him of ignoring climate change and social issues.