New US secretary of state Mike Pompeo has hit the ground running at Nato headquarters on his first trip abroad as America's top diplomat.
Just hours after being sworn in, Mr Pompeo flew to Brussels where the alliance's foreign ministers are meeting to prepare a leaders' summit in July.
"I did come straight away, I was sworn in yesterday and I hopped on a plane," Mr Pompeo told Nato Secretary General Jens Stoltenberg as he arrived.
"There's good reason for that. The work that's being done here today is invaluable and our objectives are important and this mission means a lot to the United States of America. The president very much wanted me to get here and I'm glad we were able to make it, and I look forward to a productive visit here today."
Mr Stoltenberg said Mr Pompeo's presence at the meeting so soon after taking the reins of the US State Department was "a great expression of the importance of the alliance and the importance we attach to the alliance".
"I very much look forward to talking with you, on the need to adapt Nato to a more demanding security environment," he added.
A senior US official said Mr Pompeo's aim is to ensure that Nato maintains a unified position of "no business as usual" with Russia and to prod members, particularly Germany, to meet their commitments to spend 2% of their gross domestic product on defence by 2024.
That commitment was made in 2014 and thus far only six of the 28 countries who made the pledge meet the goal. Nine have produced realistic plans for reaching it by 2024, but the rest, including Germany, have not.
That spending level, frequently incorrectly referred to by Mr Trump as a contribution to Nato itself, is particularly important given the allies' need to combat increased Russian aggression, said the official.
The official said the US delegation would make the point that Nato is more relevant today than at any point since the end of the Cold War.
Russian efforts to destabilise Western democracies as well as encroach on neighbours like Ukraine will be a major theme of the meeting, the official said. The ministers will hold sessions on Russia, Afghanistan and Nato's "open door policy" for accepting new members.
In addition, Mr Pompeo will have separate talks with the foreign ministers of Italy and Turkey. Relations with the latter are notably strained. The senior official said one of Mr Pompeo's main goals with Turkish foreign minister Mevlut Cavusoglu is to refocus on co-ordination in northern Syria, where Turkey has been attacking Kurdish rebels supported by the US.
That co-ordination was started by Mr Pompeo's predecessor, Rex Tillerson, who was fired by Mr Trump last month, and had languished in the absence of a new secretary of state.