“Another terrorist attack in Paris. The people of France will not take much more of this,” he tweets.

United States President Donald Trump is taking the unusual step of weighing in publicly on a foreign presidential election, predicting that the latest attack in Paris will have a “big effect” on voters there.

“Another terrorist attack in Paris. The people of France will not take much more of this. Will have a big effect on presidential election!” he tweeted on the Islamic State-claimed attack in which the assailant used an automatic weapon to shoot officers in the center of the Champs-Elysees and one officer was killed as was the gunman.

It is being keenly watched

The outcome of France’s presidential election is being closely watched for signs that Europe is moving toward nationalist candidates who advocate the European Union’s dissolution. The top two candidates from Sunday’s vote in Paris will progress to a winner-takes-all May 7 run-off.

Mr. Trump was a supporter of the British decision to exit the European Union and has stated his preference for one-on-one trade and defence agreements with U.S. allies.

On Thursday, Mr. Trump met with Italian Premier Paolo Gentiloni. At a joint news conference, he said Iran was failing to fulfil the “spirit” of its nuclear deal with world powers and that the 2015 deal shouldn’t have been signed.

“They are not living up to the spirit of the agreement, I can tell you that,” Mr. Trump said of the Iranians on Thursday, though he did not mention any specific violations. Earlier this week, the administration certified to the Congress that Iran was complying at least technically with the terms of the deal, clearing the way for Iran to continue enjoying sanctions relief in the near term.

Mr. Trump’s wrangling on foreign policy issues abroad comes amid debate in the U.S. over his priorities at home. White House budget director Mick Mulvaney said money for Mr. Trump’s border wall must be part of the legislation, along with funds to hire more immigration agents.

Nearing Day 100 in office

Mr. Trump is approaching his 100th day in office, a benchmark often cited to measure a new administration’s achievements. On Friday, he declared the benchmark as a “ridiculous standard.”

Since taking office, Mr. Trump has managed to get a Supreme Court justice confirmed and is pursuing tougher regulations on immigration. But his health care bill didn’t come up for a vote in the House and his travel ban was blocked in the courts.