Special U.S. envoy Steve Witkoff says Russian leader Vladimir Putin agreed at his summit with President Donald Trump to allow the U.S. and European allies to offer Ukraine a security guarantee resembling NATO’s collective defense mandate as part of an eventual deal to end the 3 1/2-year war.

The traditionally Russian-speaking area is at the heart of what the Russian president calls the “root causes” of the war, and taking it over is near the top of his list of territorial and political demands.