U.S. President Donald Trump meets with Ukraine's President Volodymyr Zelenskyy on the sidelines of the NATO summit in Ankara, Turkey, Wednesday. (AP Photo/Alex Brandon)

ANKARA, Turkey (AP) — U.S. President Donald Trump said at a NATO summit Wednesday in Turkey that the U.S. will give Ukraine a license to make Patriot air defense systems to counter missile attacks from Russia in their more than four-year war, a huge coup for Kyiv which has long requested the technology.

Allowing foreign manufacture of Patriots, which the U.S. had resisted, was a turnaround for Trump that mirrored his day at the NATO meeting: Upon arriving, he lashed out at European partners for resisting his efforts to take control of Greenland and for not supporting his war in Iran. But by day’s end, he described a gathering of unity and “tremendous love,” and praised member nations on their progress in increasing their defense spending.

NATO’s European members plus Canada have scrambled to meet the alliance’s increased defense spending targets, which Trump has demanded as the U.S. draws down troops in Europe and insists the continent take more responsibility for its own security.

Trump had reopened old wounds among the 32 NATO leaders by insisting again ahead of the summit that the U.S. should control Greenland, a semiautonomous Danish territory. That led Denmark’s Prime Minister Mette Frederiksen to say her country is “ready to defend every inch of NATO including our own territory.”

Trump also blasted some European countries for refusing to participate in the Iran campaign, singling out Spain as “a terrible partner in NATO” and renewing his threats to cut off trade.

But the tone of Trump’s meeting with the Ukrainian President Volodymyr Zelenskyy was a break from earlier encounters which ended in acrimony, and Trump praised the Ukrainian leader’s willingness to reach a deal on ending the fighting in Ukraine.

“We’ve actually developed a good relationship. It’s hard to believe,” Trump said during a news conference with Zelenskyy, adding that he believed a deal on ending the war was on the horizon and that the U.S. would “work on some kind of security package” to provide to Ukraine.

Trump said the Ukrainian president has “done an amazing job” and “been very effective” in the war as he pledged to grant Ukraine a license to manufacture the Patriot defense systems.

“We’ll give them the right to make Patriots. We’ll show them how to do it,” Trump said. “I think they can produce them pretty quickly.”

Patriots are expensive, in high demand and take a long time to produce. Zelenskyy has for years been asking for more of them, and more recently for a license so that Ukraine can manufacture its own.