WASHINGTON, July 13 (Xinhua) -- U.S. President Donald Trump said Monday that the United States was reinstating a naval blockade on Iran in the Strait of Hormuz.

"We are reinstating the THE IRANIAN BLOCKADE, so named because it is only stopping Iran's ships or customers from entering or leaving," Trump wrote on Truth Social.

He claimed that the United States would serve as the "guardian" of the Strait of Hormuz and would impose a 20 percent toll on all cargo shipped through the strategic waterway.

The toll would help cover "any and all costs necessary to do the job of providing safety and security to this very volatile section of the World," Trump said. "The process and formation will begin immediately."

Traffic in the strait has plummeted as renewed strikes between the U.S. and Iran heightened safety concerns. Maritime data firm Kpler said 14 ships transited the strait on Sunday, the fewest in a month.