KYIV, Ukraine (AP) — U.S. President Donald Trump’s special envoy Keith Kellogg said in Kyiv on Monday that officials are “working very, very hard” on efforts to end the three-year war between Russia and Ukraine, as a lack of progress fuels doubts about whether a peace settlement could be on the horizon.

U.S. President Donald Trump started the week declaring a diplomatic breakthrough in his bid to prod Moscow and Kyiv closer to peace, announcing he had begun arranging for direct talks between Russia's Vladimir Putin and Ukraine's Volodymyr Zelenskyy.

Moscow continues to throw cold water on the prospect of Putin-Zelenskyy meeting, and is insisting Russia have a role in security guarantees for Ukraine.