Russian President Vladimir Putin has proposed holding “direct talks” with Ukraine on May 15 in Istanbul, as European leaders and the United States attempt to put pressure on Moscow to agree to a 30-day ceasefire in order to bring an end to the three-year conflict.

In a rare, late-night television address from the Kremlin on Saturday, Putin told Russians, “We seek serious talks... to remove the root causes of the conflict and start moving toward a lasting, strong peace,” adding that the talks should ”start without delay, as early as May 15.”

Russian President Vladimir Putin on Sunday proposed direct talks with Ukraine on May 15 in Istanbul that he said should be aimed at achieving a durable peace and eliminating the root causes of the war.