President Donald Trump "is committed to NATO" and deserves credit in obtaining $100 billion more in defense spending for the alliance, Jens Stoltenberg, the secretary general of the North Atlantic Treaty Organization, said Sunday.

"President Trump has been very clear: He is committed to NATO. He stated that clearly just a few days ago and also at the NATO summit in July," Stoltenberg said on "Fox News Sunday."

Stoltenberg's comment stands in contrast to Democrats who fear Trump wants to pull out of NATO, and some who have expressed concern he could be undermining the military alliance because it benefits Russian President Vladimir Putin.

A New York Times report earlier this month said Trump repeatedly told aides he wanted to pull out of the alliance. In response to the report, Democrats pushed for legislation requiring congressional approval of any move to leave NATO.

Trump has also been criticized for his aggressive approach in insisting America's "delinquent" allies pay a greater share toward the collective defense agreement. At the summit in July, he demanded the other members "immediately" increase their contributions.

Stoltenberg said the tough approach paid off.

"We agreed to do more to step up – and now we see the results. By the end of next year, NATO allies will add $100 billion extra toward defense," he said. "So we see some real money and some real results. And we see that the clear message from President Donald Trump is having an impact."

The president took note of Stoltenberg's interview.

"Jens Stoltenberg, NATO Secretary General, just stated that because of me NATO has been able to raise far more money than ever before from its members after many years of decline," Trump tweeted. "It’s called burden sharing. Also, more united."

The president also said Stoltenberg's interview undermined the narrative from "Dems & Fake News" who "like to portray the opposite" of his relationship with NATO.

When asked if he was concerned that Trump was "helping Putin splinter NATO," Stoltenberg said, "What I see is that actually NATO is united because we are able to adapt to deliver. North America and Europe are doing more together now than before."

Stoltenberg said Trump is helping "us adapt the alliance, which we need, because we live in a more unpredictable world."

"And you have to remember that the increase we now see in defense spending by European and NATO allies comes after years of decline. So before they were cutting billions. Now they're actually adding billions," he said.