NATO foreign ministers on Thursday debated an American demand to massively ramp up defense investment as the United States focuses on security challenges outside of Europe.

The debate on defense spending is heating up ahead of a summit of U.S. President Donald Trump and his NATO counterparts in the Netherlands on June 24-25. It’s a high-level gathering that will set the course for future European security, including that of Ukraine.

Foreign ministers from NATO member states gathered in Antalya, Turkey, on Thursday to debate a U.S. proposal to significantly boost defense spending amid growing global threats and shifting American strategic priorities.