WASHINGTON — President Trump’s plan to recognize Jerusalem as the capital of Israel ran into mounting resistance abroad on Monday, with France’s president, Emmanuel Macron, warning him it was a bad idea.

Mr. Macron joined leaders from Jordan, Egypt, Turkey and the Arab League in speaking out against the move, which would overturn decades of American policy. People briefed on the deliberations said Mr. Trump planned to address the issue in a speech on Wednesday, but they cautioned he could still change course.

In a phone call with the president, Mr. Macron “expressed his concern with the possibility that the United States might unilaterally recognize Jerusalem as capital of the State of Israel,” according to a statement issued by the French government.

“Mr. Macron,” the statement said, “reaffirmed that the status of Jerusalem must be resolved through peace negotiations between Israelis and Palestinians, and particularly those relating to the establishment of two states, Israel and Palestine, living side by side in peace and security with Jerusalem as their capital.”