President Trump said Friday he will be "strongly protecting American interests" during his first foreign trip.

"Getting ready for my big foreign trip. Will be strongly protecting American interests—that's what I like to do!" Trump tweeted.

Trump departs for his eight-day trip Friday afternoon. He'll visit five countries — Saudi Arabia, Israel, Italy, Vatican City and Belgium — and attend NATO and G-7 summits.

First lady Melania Trump will accompany him.

The president sent shockwaves through Washington, D.C., on Thursday after tweeting his criticism of the FBI's continued investigation into his associates and their potential ties to Russia.

Trump called the investigation the "single greatest witch hunt of a politician in American history."