President Trump said money is starting to "pour in" to NATO following a speech in which he scolded NATO allies for failing to contribute their fair share.

"Many NATO countries have agreed to step up payments considerably, as they should," Trump tweeted from Italy on Saturday. "Money is beginning to pour in — NATO will be much stronger."

During a speech at NATO headquarters in Brussels earlier this week, Trump said member countries must "finally contribute their fair share and meet their financial obligations."

NATO's collective agreement instructs members to spend at least 2 percent of their GDP on defense spending by 2024. But according to NATO, only five countries have met that directive: the United States, United Kingdom, Greece, Estonia and Poland.

Trump is wrapping up his first foreign trip, and will spend his last day abroad attending meetings with leaders of the G7.

The president said in a separate tweet the first item on the agenda would be terrorism.

"Big G7 meetings today. Lots of important matters under discussion. First on the list, of course, is terrorism," Trump said.