UNITED NATIONS — Already furious over President Trump’s visa ban, Iran warned the United States on Tuesday not to escalate tensions over tests of Iranian missiles — tests that his administration’s new United Nations ambassador called “absolutely unacceptable.”

The Iranian warning, made in Tehran by Foreign Minister Mohammad Javad Zarif, came a day after American and Israeli officials accused Iran of having conducted a missile test that they said had violated a United Nations Security Council resolution.

The United States called an urgent meeting of the Council on Tuesday to discuss the grievance, making Iran the subject of the first diplomatic skirmish at the United Nations by Nikki R. Haley, the former governor of South Carolina who is Mr. Trump’s new ambassador.

“The United States is not naïve,” she told reporters after the closed meeting. “We’re not going to stand by. You’re going to see us call them out as we said we would, and you are also going to see us act accordingly.”