President Trump participates in a signing ceremony for the “Iraq and Syria Genocide Relief and Accountability Act of 2018” in the Oval Office at White House on Tuesday. (Jabin Botsford/The Washington Post)

President Trump sought Wednesday to gain leverage from a terrorist attack at a Christmas market in France in a battle with Democratic congressional leaders over funding of his long-promised wall on the U.S.-Mexico border.

In a morning tweet, Trump referenced the incident in the eastern French city of Strasbourg as he made an appeal to Senate Minority Leader Charles E. Schumer (D-N.Y.) and House Minority Leader Nancy Pelosi (D-Calif.) for votes on border security.

“Another very bad terror attack in France,” Trump wrote. “We are going to strengthen our borders even more. Chuck and Nancy must give us the votes to get additional Border Security!”

Trump’s tweet came less than 24 hours after an extraordinary Oval Office meeting with Schumer and Pelosi in which they publicly sparred with Trump over his demand for $5 billion for the border wall that he made a central promise of his 2016 campaign.

Democrats have offered no more than $1.3 billion for border fencing as part of a larger budget deal.

The stunning spat — which Schumer characterized as a Trump “temper tantrum” — ended with the president declaring he would be proud to shut down the government to get the money he wants for the wall.

If the president follows through on the threat, about 25 percent of the federal government would begin to run out of money Dec. 21, putting hundreds of thousands of federal workers at risk of getting furloughed without pay just before Christmas.

During remarks Wednesday on the Senate floor, Schumer did not respond directly to Trump’s tweet but called his promised wall “a petty campaign pledge to fire up his base.”

Earlier Wednesday, the Paris prosecutor announced that the attack on France’s largest Christmas market by a gunman with a long criminal record was an act of terrorism.

A manhunt is still underway for the suspect, who was wounded during the attack and has been identified by French authorities as 29-year-old Cherif Chekatt.

Paris Prosecutor Rémy Heitz, who leads terrorism investigations, said the suspect had 27 criminal convictions in France, Germany and Switzerland. He said two people were killed outright, while a third was left in a vegetative state. The attack also wounded 13 others, eight of whom are in critical condition.

Trump’s Wednesday morning tweet was the latest in a string of presidential attacks on France, a country that seems to be earning the lion’s share of Trump’s social media ire.

Although Trump once enjoyed cordial relations with French President Emmanuel Macron — a bond once described as a transatlantic “bromance” — the honeymoon has long since ended.

Last weekend, the fourth act of France’s ongoing “yellow vest” protest over dwindling purchasing power and income inequality triggered a Trump tweet falsely claiming that thousands of citizens had taken to the streets to say no to the Paris climate agreement of 2015 and, in doing so, to honor Trump.

“Chanting ‘We Want Trump!’ ” he wrote. “Love France.”

In response, French Foreign Minister Jean-Yves Le Drian urged Trump to stop meddling in France’s domestic affairs.

The height of the tension, however, came last month, when Trump visited France for the 100th anniversary of the 1918 armistice that ended World War I.

Before disembarking from Air Force One in Paris, Trump fired off a tweet attacking Macron for allegedly suggesting that Europe create its own army to defend itself from the United States. Trump’s statement was based on a misunderstanding of what Macron had actually said: He urged the creation of a European army so that the European Union would no longer have to rely so extensively on the United States for defense support, which Trump has long advocated.

But after Macron delivered a soaring speech in favor of multilateralism — blasting the same type of nationalism that Trump has repeatedly defended — the U.S. president launched a Twitter tirade against his French counterpart, attacking in particular his low approval ratings.

In a second tweet Wednesday, Trump cited the 2015 Iran nuclear deal in trying to make his case for the southern border wall.

“The Democrats and President Obama gave Iran 150 Billion Dollars and got nothing, but they can’t give 5 Billion Dollars for National Security and a Wall?” Trump wrote.

He was referring to Iranian assets than were unfrozen by the United States as part of the deal. In exchange for lifting nuclear-related sanctions, the United States and five other world powers obtained agreement from Iran to curtail parts of its nuclear power program that raised proliferation concerns, as well as a pledge to never acquire nuclear weapons.

The actual amount of Iranian money returned to the country under the deal was significantly lower than the $150 billion stated by Trump, according to government officials and independent economists. At the time of the agreement, the Treasury Department estimated that once Iran fulfilled other obligations, it would have about $55 billion left. The Central Bank of Iran said the number was actually $32 billion.

McAuley reported from Strasbourg. Erica Werner in Washington contributed to this report.