NATO defence ministers are gathering for their first meeting with new US Secretary of Defense James Mattis in Brussels.
Speaking to the media, Mattis said the US remains committed to the Transatlantic alliance. "This is a crucial time for our Transatlantic alliance. The challenges we face are the most complex and demanding in a generation," he said.
"Neither Europe nor America can tackle them alone. A strong NATO is good for Europe and North America. And therefore, I welcome the US commitment to the Transatlantic bond," Mattis added.
Calling the alliance "a fundamental bedrock" for the United States, he tried to reassure allies concerned about President Donald Trump's commitment to the bloc.
"President Trump stated he has strong support for NATO," he said.
For more on this, TRT World's Elena Casas has more from Brussels.
NATO Secretary General Jens Stoltenberg also said a strong NATO is good for Europe and for North America.
On Tuesday, the NATO chief announced that the alliance's European and Canadian members had increased defence spending by 3.8 percent last year, around $10 billion more than in 2015.
Stoltenberg added that the top priority for the Transatlantic alliance is to increase defence spending, as demanded by President Trump, and this will be one of the main topics at a NATO summit in May, where Trump will be in attendance.
NATO set the target for defence spending for its members at 2 percent of GDP, after Russia's annexation of Crimea from Ukraine in 2014.
But in 2015, only Britain, Poland, Greece and Estonia met the goal. Stoltenberg said that Latvia, Lithuania and Romania are moving towards the target, and Germany is also increasing spending, but noted that "some allies are still really struggling."