The fast-moving developments in Trump's near-back-to-back summits with the heads of Russia, Ukraine and European powers have highlighted a pair of repeated sticking points.

Western defense companies are increasingly establishing new presences in Ukraine and working directly with Ukrainian companies.

President Donald Trump on Sunday night declared that Kyiv would not be regaining Moscow-annexed Crimea, nor would it be allowed to join NATO.

As Trump pushes for peace, Ukraine accuses Russia of a deadly drone and missile strike, "as if there were no efforts by the world to stop this war."

Putin is sticking, too, to his previous demands that Ukraine give up its NATO ambitions and for a legally binding pledge from the U.S.-led military alliance that it will not expan

U.S. military leaders are expected to meet with their NATO counterparts Wednesday to discuss potential security guarantees for Ukraine. Ukrainian President Volodymyr Zelenskyy has stressed that strong security guarantees are key to lasting peace,

Special U.S. envoy Steve Witkoff says Russian leader Vladimir Putin agreed to allow the U.S. and Europe to offer Ukraine a security guarantee resembling NATO's collective defense mandate.