Negotiations to end Russia's invasion of Ukraine are showing signs of progress, but major challenges remain, according to a senior Kremlin official.

Ukraine's Zelenskyy calls recent US-Russia-Ukraine talks in Abu Dhabi "constructive," marking potential breakthrough in diplomatic efforts to end the war.

The talks are the first known instance that officials from the Trump administration have sat down with Russia and Ukraine.

Ukrainian President Volodymyr Zelenskyy blasted his European allies Thursday for what he portrayed as the continent’s slow, fragmented and inadequate response to Russia’s invasion nearly four years ago and its continued international aggression.

Ukrainian President Volodymyr Zelenskyy criticized Europe's response ​to the Greenland dispute with the U.S., saying the ​continent needed to show more courage ⁠and describing it ‍as ⁠a "fragmented ​kaleidoscope" of small and middle powers.

Ukrainian, Russian and U.S. envoys are meeting in the United Arab Emirates, the first known instance that officials from the Trump administration have sat down with both countries as part of Washington’s push to end Moscow’s nearly 4-year-old invasion.

Ukraine's president, Volodymyr Zelenskyy, has attacked Europe as weak in the face of the U.S. and President Donald Trump.