The North Atlantic Treaty Organization - or NATO - has been shaken by Donald Trump's "American First" promise and his mistrust of international institutions. The US president once again blasted members of the 29-nation alliance for failing to spend their fair share. Zhang Dan has more.

Pay your fair share or else! During a rally in South Carolina, Trump lashed out at Washington's NATO allies for not contributing enough and claimed the US is paying too much.

DONALD TRUMP US PRESIDENT "It's all going to work out because we're the piggy bank that they like to take from. Whether it's military protection. You look at NATO. NATO. We're spending 90 percent of NATO. Now it's all wonderful and we like to help out. But it helps them. They're in Europe. It helps them a lot more than it helps us. We're very far away."

Trump singled out Germany, saying the country, as an important NATO member, has to pay more.

DONALD TRUMP US PRESIDENT "Germany is paying 1 percent of a much smaller GDP. We're paying close to 4 percent of a much larger GDP. Now that doesn't work folks."

Trump's hard stance on the NATO defense budget has angered US allies in Europe. Defense ministers from nine EU member states met in Luxembourg on Monday and signed a joint military intervention policy. As the policy was established outside both the EU and NATO frameworks, it would allow co-signatories react to situations near Europe's borders without the need to secure support from the United States. Zhang Dan, CGTN.