Here is a look at some of Mr. Trump’s more high-profile threats.

Closing the border with Mexico

In retreating from his threat to close the border, Mr. Trump was withdrawing the warning that he issued strongly last week. But on Friday, he offered up another one. He said that the trade deal that the United States had reached with Mexico and Canada, known as the U.S.M.C.A., would not apply if Mexico does not stop Central American migrants from illegally entering the United States.

“If for any reason Mexico stops apprehending and bringing the illegals back to where they came from, the U.S. will be forced to Tariff at 25% all cars made in Mexico and shipped over the Border to us. If that doesn’t work, which it will, I will close the Border,” Mr. Trump wrote on Twitter.

“This will supersede USMCA,” Mr. Trump added. He also threatened an “economic penalty” on Mexico “for the 500 Billion Dollars in illegal DRUGS that are shipped and smuggled through Mexico and across our Southern Border.”

Congress has not yet voted on the trade deal. If it does approve the pact — and the president tried to unilaterally abrogate selective provisions of the agreement — it would provoke numerous legal challenges, as well as an uproar from foreign leaders and members of Congress.

A bullhorn to Russia

The president warned Russia in March to “get out” of Venezuela after Moscow dispatched military personnel to the country and offered to send the government of President Nicolás Maduro shipments of food and medicine. He has consistently said that Mr. Maduro must step down and has strongly suggested that United States military intervention was on the table. He also urged the Venezuelan military to rebel. None of those threats have been effective. Mr. Trump has accused the Russian government of bolstering Mr. Maduro while the United States has been rallying support behind Juan Guaidó, the opposition leader.