The Secretary-General of NATO assured Thursday that all members of the alliance had heard the president of the United States' calls to increase defense spending, after a series of urgent talks on their financial contributions.

In a speech at the end of a two-day summit, Jen Stoltenberg said the alliance had taken major decisions and praised that since Donald Trump took office, European countries and Canada had increased defense spending by an additional $41 billion.

"All allies have heard Trump’s message loud and clear. We understand that this American president is very serious about defense spending and this is having a clear impact," he said.

Trump has previously denounced that his is one of the few countries that paid the agreed-on 2 percent of the GDP for defense and has called on other members to raise their spending.

On Friday he forced an interruption in the summit to hold an emergency meeting on spending.

NATO members had agreed at a summit in 2014 to grant 2 percent of their GDP to defense by 2024, a target that has become the US president's greatest demand and that he has forced into the center of any discussion at alliance meetings.