FIGHTING

* Eight missiles struck Mykolaiv, a river port just off the Black Sea, its mayor said, including a hit on an apartment building, that killed four people and wounded five.

* "There is fighting everywhere," said the governor of the eastern Luhansk region, much of which is now in Russian hands. The Russians were taking the city of Lysychansk building by building, he said, as they did before in nearby Sievierodonetsk.

* Ukraine carried out its biggest exchange of prisoners of war since Russia invaded, securing the release of 144 of its soldiers, including 95 who defended Mariupol's steelworks, Ukraine's military intelligence agency said.

DIPLOMACY AND ECONOMY

* NATO invited Sweden and Finland to join the military alliance in one of the biggest shifts in European security in decades after Turkey lifted its veto.

* In reaction, President Vladimir Putin said Russia would respond in kind if NATO deployed troops and infrastructure in Finland and Sweden after they join the alliance.

* US President Joe Biden pledged more American troops, warplanes and warships for Europe as NATO agreed the biggest strengthening of its deterrents since the Cold War in response to Russia's invasion of Ukraine.

* Britain will provide another Stg1 billion ($A1.8 billion) of military support to Ukraine, the British government said, bringing the total amount to Stg2.3 billion since the invasion.

QUOTES

"This not a war being waged by Russia against only Ukraine. This is a war for the right to dictate conditions in Europe - for what the future world order will be like," President Volodymyr Zelenskiy told NATO leaders in a video link-up from Kyiv.

* "My combat experience here was that one mission on that one day," said Alexander Drueke, former US soldier captured in eastern Ukraine. "I didn't fire a shot. I would hope that would play a factor in whatever sentence I do or don't receive."

Australian Associated Press