It was not clear whether Trump was threatening a U.S. withdrawal from NATO, but some diplomats perceived his comments that way.

Trump told NATO leaders that if they did not meet their defense spending targets of 2 percent of gross domestic product by January, the United States would go it alone, according to two officials briefed on the meeting. The officials said Trump threatened to “do his own thing.”…

Asked at a news conference whether he could withdraw the United States from NATO without congressional approval, Trump replied, “I think I probably can, but that’s unnecessary.” He added: “The people have stepped up today” as they never have before. “Everyone in the room thanked me. There was a great collegial spirit in that room. . . . Very unified, very strong. No problem.”