By Rebecca Ballhaus and Michael R. Gordon

WASHINGTON -- President Trump on Monday signed an executive order imposing new sanctions on Iran, including against its supreme leader and its foreign minister.

Speaking to reporters in the Oval Office, where he signed the order, Mr. Trump described the sanctions as hard-hitting and said they would deny Iran's supreme leader, Ayatollah Ali Khamenei, Foreign Minister Javad Zarif and others access to financial instruments.

"We will continue to increase pressure on Tehran," the president said. He said he was not seeking a conflict with Iran. "I think a lot of restraint has been shown by us -- a lot of restraint -- and that doesn't mean we're going to show it in the future."

The move came on the same day the Trump administration said it is planning to try to assemble an international coalition to protect shipping in the Persian Gulf, senior State Department officials said Monday.

However, officials did not spell out the precise role other countries would take, saying they would serve as observers, deterring Iranian attack by watching and taking photographs of Iran's operations.

"This is having eyes on," said one State Department official, who is traveling with Secretary of State Mike Pompeo in Saudi Arabia. "So it's not about shooting at people. It's about shooting pictures of Iranians."

"The U.S. will participate," added the State Department official, who noted that the effort is being dubbed the "Sentinel program."

The intent to set up a joint effort came after Mr. Trump questioned in a pair of tweets Monday why the U.S. should play any role in protecting ships in the Gulf, noting that the U.S. has provided such protection for years "for zero compensation."

"All of these countries should be protecting their own ships on what has always been...a dangerous journey," he wrote on Twitter on Monday, noting China and Japan specifically.

He also said that the U.S. is becoming a self-sufficient energy producer and no longer needs to be in the region.

"We don't even need to be there in that the U.S. has just become (by far) the largest producer of Energy anywhere in the world!" he wrote.

The decision to impose sanctions follows mounting tensions between the U.S. and Iran in recent weeks. Washington has blamed Tehran for attacks on tankers, while Tehran downed a U.S. drone and has threatened to violate some terms of the 2015 nuclear deal from which Mr. Trump withdrew the U.S. in May 2018.

Asked if he was imposing the sanctions in response to the downed drone, Mr. Trump said one "could probably add that into this," but said the sanctions were "something that was going to happen anyway."

Treasury Secretary Steven Mnuchin said afterward at a briefing at the White House that the sanctions were both in response to the downing of the U.S. drone and in keeping with previous plans.

The U.S. is pressing a campaign of economic pressure and seeking ultimately to drive Iran's oil exports to zero. It has more recently imposed sanctions on Iran's industrial-metals sector and announced major sanctions on one of the country's biggest petrochemical companies.

Write to Rebecca Ballhaus at Rebecca.Ballhaus@wsj.com and Michael R. Gordon at michael.gordon@wsj.com

(END) Dow Jones Newswires

June 24, 2019 13:25 ET (17:25 GMT)

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