Feb. 15 (UPI) -- Defense Secretary Jim Mattis said Wednesday the NATO alliance is the "fundamental bedrock for the U.S. and all the transatlantic community" but told allies they must boost their defense spending or the United States may change its relationship.
Mattis met privately with defense ministers from other NATO countries in Brussels. Statements were provided to reporters traveling with the defense secretary.
"I owe it to you all to give you clarity on the political reality in the United States and to state the fair demand from my country's people in concrete terms," Mattis said. "America will meet its responsibilities, but if your nations do not want to see America moderate its commitment to the alliance, each of your capitals needs to show its support for our common defense."
President Donald Trump said during his election campaign he wanted the NATO nations to "pay their fair share."
The 28 countries have pledged to spend at least 2 percent of their gross domestic product on defense, but just five meet that benchmark: Greece (2.38), Great Britain (2.21), Poland (2.2), Estonia (2.16) and the United States (3.16).
The United States spent $650 billion on defense in 2015, according to NATO. The total spending by NATO nations was $900.5 billion.
Germany has contributed only 1.19 percent and would need to boost its defense spending about $75 billion per year to reach the 2 percent target. Canada was 10th at 0.99 percent.
"No longer can the American taxpayer carry a disproportionate share of the defense of Western values," Mattis, a former general, said. "Americans cannot care more for your children's security than you do. Disregard for military readiness demonstrates a lack of respect for ourselves, for the alliance and for the freedoms we inherited, which are now clearly threatened."
British Defense Secretary Michael Fallon, who met one on one with Mattis before the main NATO meeting, agrees on spreading the burden.
"An annual increase would at least demonstrate good faith," Fallon told reporters. Britain spent $60 billion on defense in 2015.
Britain's sentiment comes at it prepares to leave the European Union.
NATO Secretary General Jens Stoltenberg agreed "fairer burden-sharing" is necessary.
Spending among European allies and Canada increased 3.8 percent in 2016 -- about $10 billion.
"This is significant, but it is not enough," he said. "We have to continue to increase defense spending across Europe and Canada. So, we need to keep the momentum."
Mattis, a former NATO commander, said it's important for the alliance to remain strong.
"It is ultimately freedom we defend at NATO. I do have confidence that we will prove once again that we can react to the changing circumstances," he said.
"We've done so in the past and there's every reason and confidence that we will move out fully together once again."