President Trump is taking the unusual step of weighing in publicly ahead of 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! — Donald J. Trump (@realDonaldTrump) April 21, 2017

His tweet Friday comes as he tries to bolster U.S. support for hard-line proposals on immigration and foreign policy. Mr. Trump’s administration is demanding that Congress fund a bigger U.S. border wall with Mexico and is suggesting that his administration could scrap the U.S. nuclear deal with Iran.

On Thursday, an attacker in Paris used an automatic weapon to shoot officers in the center of the Champs-Elysees. One officer was killed, and police shot and killed the gunman after he had seriously wounded two others. The Islamic State claimed responsibility for the attack.

Mr. Trump was asked about the shooting Thursday during a press conference with the Italian prime minister -- he said it “looks like another terrorist attack” and added, “What can you say? It just never ends. We have to be strong and we have to be vigilant.”

The shooting occurred just before France’s presidential election this weekend, which 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 May 7 runoff.