A still-unfolding diplomatic road seeking peace in Ukraine has had many twists and turns

It was a weekend of diplomatic announcements on the war in Ukraine.

First, European leaders assembled in Kyiv on Saturday with President Volodymyr Zelenskyy to put pressure on Russian President Vladimir Putin for a ceasefire. Then, after midnight, the Kremlin leader surfaced in Moscow to unveil a proposal for talks in Istanbul, Turkey.

If both Putin and Zelenskyy sit down with each other, it would be a first in the 3-year-old war.

Key events that have shaped efforts to end the war since Russia invaded Ukraine on Feb. 24, 2022:

Feb. 28, 2022: Ukrainian and Russian delegations meet in neighboring Belarus for the first time after the invasion. Talks continue over the next two weeks, but no apparent agreements emerge other than a decision to set up humanitarian corridors for civilians.

March 21, 2022: Zelenskyy calls for direct talks with Putin but is rebuffed by Russian Foreign Minister Sergey Lavrov. A day later, Zelenskyy says he is prepared to discuss a commitment for Ukraine to not to seek NATO membership in exchange for a ceasefire, the withdrawal of Russian troops and a guarantee of Ukraine's security.

March 29, 2022: Talks begin in Istanbul, Turkey, with Moscow saying it's willing to ''fundamentally cut back'' military activity near Kyiv and the northern city of Chernihiv, while Ukraine said it was open to discussing neutral status for Ukraine if its security is backed by other nations.

April 7, 2022: Lavrov rejects a Ukrainian peace proposal as ''unacceptable. '' He says Kyiv has walked back on an agreement to exempt the Crimean Peninsula from wider Ukrainian security guarantees. Russia illegally annexed Crimea in 2014.

April 26, 2022: U.N. Secretary-General António Guterres visits Russia to discuss ending the war.

May 13, 2022: U.S. Defense Secretary Lloyd Austin calls his Russian counterpart, Sergei Shoigu, in their first contact since before the start of the war.

July 22, 2022: Russia and Ukraine, with mediation by Turkey and the U.N., agree on a deal to unblock supplies of grain stuck in Ukraine's Black Sea ports, ending a standoff that threatened global food security. The deal expires a year later.

Sept. 22, 2022: Zelenskyy addresses the U.N. General Assembly, laying out five ''nonnegotiable'' conditions, including a ''just punishment'' for Russia.

Sept. 30, 2022: Russia illegally annexes the Ukrainian regions of Donetsk, Luhansk, Zaporizhzhia and Kherson, even though it doesn't fully control any of them. Ukraine responds by applying to join NATO and by enacting a decree that declares negotiations with Putin ''impossible''.

Nov. 15, 2022: Zelenskyy unveils a 10-point peace plan at the G20 summit in Bali.

June 25, 2023: Officials from 15 countries, including the U.S., the European Union, India, Brazil, South Africa, Saudi Arabia, and Turkey meet in Copenhagen, Denmark, to discuss Zelenskyy's peace plan.

Aug. 5, 2023: Two days of discussions on the war begin in Saudi Arabia with delegates from 40 countries, but not Russia. No joint statements are issued.

Oct. 28, 2023: Delegates from 65 countries meet in Malta to continue talks on Zelenskyy's peace plan. Russia, which has dismissed the talks, was not invited.

June 15, 2024: Representatives of 92 nations meet in Nidwalden, Switzerland, to discuss Ukraine's peace plan. Despite the growing number of delegates, a consensus remains elusive. The summit's final statement is backed by most – although not all – participants.

Dec. 7, 2024: U.S. President-elect Donald Trump travels to Paris and meets Zelenskyy and other European leaders.

Feb 12. 2025: Trump and Putin speak directly via telephone and agree to begin negotiations on ending Ukraine war in a phone call that abruptly ended a three-year U.S.-led effort to isolate Putin over Ukraine.

Feb. 18, 2025: Russian and U.S. officials, including Lavrov and U.S. Secretary of State Marco Rubio, meet in Saudi Arabia and agree to work toward ending the war, as well as restoring bilateral ties. Ukrainian officials are not invited.

Feb. 28, 2025: Zelenskyy meets with Trump, Rubio and Vice President JD Vance in the White House but tensions break out in the Oval Office and a proposed minerals deal between the countries is left unsigned.

March 11, 2025: U.S. and Ukrainian officials meet in Saudi Arabia, with American officials putting forward a plan for a 30-day ceasefire. Kyiv agrees to the proposed truce.

March 13, 2025: Putin effectively rejects the ceasefire plan, stating certain issues still must be resolved. He also meets with U.S. envoy Steve Witkoff in Moscow. Witkoff would travel to Russia two more times in April to meet Putin.

March 18, 2025: A proposal is put forward for a temporary halt on strikes on energy infrastructure. Both sides agree to the plan, but soon accuse each other of violations, and the measure later expires.

April 19, 2025: Putin announces a 30-hour ceasefire to mark the Easter holiday, although attacks continue across Ukraine.

April 28, 2025: The Kremlin declares a unilateral 72-hour ceasefire starting May 8 to mark Russia's Victory Day celebrating the defeat of Nazi Germany in World War II. Kyiv does not agree, preferring a 30-day truce proposed by U.S. officials. Both sides accuse each other of violating it.

May 10, 2025: French President Emmanuel Macron, British Prime Minister Keir Starmer, German Chancellor Friedrich Merz and Polish Prime Minister Donald Tusk meet with Zelenskyy in Kyiv and urge Russia to enact a 30-day truce starting May 12.

May 11, 2025: Putin proposes restarting direct talks with Ukraine in Istanbul on May 15, ''without preconditions,'' but does not agree to the 30-day ceasefire Zelenskyy challenges Putin to meet personally in Turkey.

May 12, 2025: Trump says he is ''thinking about flying over'' to Turkey for the talks after his visit to Qatar and the United Arab Emirates but later says Rubio and other U.S. officials will go.

May 13, 2025: Ukrainian presidential adviser Mykhailo Podolyak says Zelenskyy won't meet with any representative of Russia in Turkey except for Putin. Zelenskyy says he and Turkish President Recep Tayyip Erdogan will wait for Putin in Ankara, adding: ''If Putin does not arrive and plays games, it is the final point that he does not want to end the war.''