Top U.S. and European defense officials spent much of this week privately discussing possible military options in Ukraine that would bolster the Eastern European country’s protections against Russia as part of a broader peace agreement.

BRUSSELS (AP) — NATO defense chiefs were due to hold a virtual meeting Wednesday, a senior alliance official said, as Western countries pushing for an end to Russia’s war on Ukraine devise possible future security guarantees for Kyiv that could help forge a peace agreement.

Ukraine has begun developing the military component of future security guarantees as the U.S. signals Europe must take the lead role in providing them.