Key developments on May 13: * Germany's Merz threatens 'significant tightening' of Russia sanctions ahead of Ukraine peace talks * Rubio to attend Ukraine, Russia peace talks in Istanbul, Trump says * Zelensky to meet Erdogan in Turkey where both will wait for Putin ahead of peace talks * Ukraine reports destroying Russian Buk air defense system, Uragan rocket launcher * Former nuclear power plant employee arrested for allegedly helping Russia's GRU target drone strikes The European Union

Presidential Office chief Andriy Yermak said Ukraine is "ready to discuss anything," but "only if a ceasefire is achieved."

U.S. President Donald Trump's special envoys, Steve Witkoff and Keith Kellogg, will travel to Istanbul for possible peace talks between Ukraine and Russia, Reuters reported on May 13, citing three undisclosed sources.

Russia will announce its representative for the expected talks in Istanbul once Putin "deems it necessary," the Kremlin said.

President Volodymyr Zelensky would not meet any other Russian official apart from Russian President Vladimir Putin in Istanbul this week, presidential advisor Mykhailo Podolyak said on the Breakfast Show program on May 13.

The number includes 1,070 casualties that Russian forces suffered over the past day.

"We agreed to pursue ambitious measures to reduce Russia's ability to wage war by limiting Kremlin revenues, disrupting the shadow fleet, tightening the Oil Price Cap, and reducing our remaining imports of Russian energy."

Key developments on May 12: * Trump says 'both leaders' will be at Russia-Ukraine peace talks in Istanbul * Russia ignores May 12 ceasefire proposal, Ukraine tells allies at London meeting * 'Clock is ticking' — Germany gives Russia until midnight to implement ceasefire, threatens sanctions * EU to unveil new sanctions against Russia on May 14, source says * EU to send extra $1 billion from frozen Russian asset profits for Ukraine's defense U.S. President Donald Trump expressed optimism t

Beijing supports all efforts toward achieving peace in Ukraine, Chinese Foreign Ministry spokesperson Lin Jian said on May 12 when asked about Kyiv and Europe's proposal for a 30-day truce.

"I invited His Holiness to make an apostolic visit to Ukraine. Such a visit would bring real hope to all believers and to all our people," Zelensky said.

A Russian drone hit a civilian freight train in Donetsk Oblast on May 12 and injured its driver, Ukrainian Railways said amid Kyiv's calls for a ceasefire.

The number includes 1,170 casualties that Russian forces suffered over the past day.

Key developments on May 11: * Zelensky ready to meet Putin in Turkey, calls for immediate ceasefire * Trump urges Ukraine, Russia to hold direct talks 'immediately' * US, European leaders resoundingly reject Russia's proposal for talks without ceasefire first * Russia launches overnight drone attack across Ukraine, damaging civilian infrastructure President Volodymyr Zelensky on May 11 said he is ready to meet Russian President Vladimir Putin in Turkey on May 15. "There is no point in pro

The number includes 1,310 casualties that Russian forces suffered over the past day.

The announcement follows mounting fears that the two nuclear-armed countries were on the brink of engaging in another full-scale war.