US President Donald Trump said Friday that the United States is committed to the NATO treaty's crucial Article Five mutual defense pledge.
Amid worries by European allies that the US leader had not fully bought in to the Atlantic treaty, Trump told reporters "I'm committing the United States to Article Five. Certainly we are there to protect."
"That's one of the reasons that I want people to make sure we have a very, very strong force, by paying the kinds of money necessary to have that force," Trump said.
The US president stunned Europe's leaders at a summit Brussels on May 25 when he failed to publicly endorse the now 29-member NATO treaty's founding mutual defense guarantee.
Instead he castigated the allies for failing to pay their way with contributions to NATO forces, singling out especially Germany.
According to Politico, Trump's defense and security advisors had included in his prepared speech a clear endorsement of the mutual defense pledge, but Trump himself struck it out just before speaking.
Doubts have remained since then despite US diplomats and military leaders themselves restating the pledge.
Just days before his January 20 inauguration, Trump rocked the post-World War II western alliance by calling NATO "obsolete."
Article Five has been the core of the NATO treaty's strength since it was formed amid a budding Cold War with communist states -- particularly the Soviet Union -- in 1949.
It has only been invoked once -- in support of the United States, after the September 11, 2001 attacks.
Speaking beside Romanian President Klaus Iohannis at a White House press conference Friday, Trump suggested his pressure on other NATO members had had an effect.
"As you know, I have been an advocate for strengthening our NATO alliance through greater responsibility and burden sharing among member nations," he said.
"Because of our actions, money is starting to pour in to NATO.... Other countries are starting to realize that it's time to pay up. And they're doing that. Very proud of that fact."
"Because together we can confront the common security challenges facing the world," he added.
Trump praised Iohannis for boosting his country's defense spending. Romania joined the NATO alliance in 2004.
"We hope our other NATO allies will follow Romania's lead," Trump said.
Iohannis said NATO's mutual defense commitment was a crucial part of a defense against an aggressive Russia.
"In my opinion, we have to be very clear, very simple, very straightforward if we talk about Russia, and with Russia," he said.
"In my opinion, we need dialogue. But on the other hand, we need what we all together decided in NATO -- a strong deterrence."