United Nations (UN) agencies on Tuesday launched an emergency appeal to respond to soaring humanitarian needs following Russia's military operation in Ukraine, calling for $1.7 billion to help people who have fled the country and those still inside.

Martin Griffiths, under-secretary-general for Humanitarian Affairs and Emergency Relief Coordinator, told reporters that the crisis has turned very ugly very fast.

The UN High Commissioner for Refugees said 150,000 more people had fled the country in the last 24 hours, bringing the total number of refugees to around 677,000.

European Commission President Ursula von der Leyen promised on Tuesday to commit at least 500 million euros ($557.96 million) from the European budget for humanitarian assistance.

France will offer 100 million euros in financial aid to populations hit by the conflict in Ukraine, the French foreign ministry said in a statement on Tuesday.

(With input from Reuters)