New Delhi, Dec. 5 -- The latest U.S. push to end Russia's nearly 4-year-old war in Ukraine has unleashed a frenzy of diplomatic activity.

Negotiators and officials from the U.S., Ukraine and Russia have crisscrossed the globe in recent weeks in a flurry of meetings to discuss a potential deal.

Here is a timeline of key talks.

Nov. 19: Ukrainian President Volodymyr Zelenskyy travels to Turkey in what he said was an effort to jump-start negotiations on ending the war. Reports emerge soon after of a 28-point peace plan drafted by the U.S. and Russia that critics say leans heavily in Moscow's favor.

Nov. 20: U.S. Army Secretary Dan Driscoll travels to the Ukrainian capital and meets Zelenskyy to brief him on the U.S.-backed peace proposal...