Russia launched a full-scale invasion of Ukraine on February 24, 2022, and Russian President Vladimir Putin expected to conquer the entire country within days, but what happened instead was three years of intense fighting thanks to the Ukrainian armed resistance with aid coming from Western allies.
The Russian military aggression against Ukraine was immediately condemned by the US and Europe, imposing sanctions on Moscow.
At the start of the war in February 2022, Ukraine held off Russian troops from the capital Kiev, and later secured victories in parts of the northeastern Kharkiv and southern Kherson regions. But it also suffered heavy losses in the eastern areas around Donetsk and Bakhmut.
For three years of war, millions of Ukrainians have fled their homes, either to other parts of Ukraine or to other countries.
Just over 6.3 million Ukrainian refugees live in Europe, including about 1.2 million in Germany, nearly 1 million in Poland and 390,000 in the Czech Republic, according to data through the end of 2024 from the UN refugee agency.
There were 1.2 million Ukrainian refugees living in Russia, according to the latest UN estimate as of June 2024.
More than 40,000 civilians have been killed or injured in Ukraine during the conflict, with many of the deaths caused by explosive weapons, according to the UN Human Rights Office. At least half of those killed - 6,203 - were adult men and 669 were children.
The US has been the single largest contributor of funding to Ukraine since the start of the war, with around $95 billion in military, humanitarian and financial aid.
Donald Trump was critical of US funds being sent to Ukraine during his 2024 campaign, and after taking office in January 2025 the US president is pushing for a quick end to the war by holding negotiating meetings with Russia in Riyadh without Ukraine or Europe.
Recently, Trump has suggested taking a transactional approach to aid, saying the US should have access to rare earth minerals in return, which Zelensky has rejected, saying any such deal must include clear security guarantees from the United States.