FIGHTING

* Ukrainian troops had recaptured the settlements of Cherkaski Tyshky, Ruski Tyshki, Borshchova and Slobozhanske, in a pocket north of Kharkiv in recent days, according to a spokesperson for the main Ukrainian force near Kharkiv.

* Luhansk Governor Serhiy Gaidai said the region was attacked 22 times during the previous 24 hours.

* In the southern port of Mariupol, Russian forces continued their assault on the Azovstal steel plant where the city's last defenders are holed up. An aide to the mayor said at least 100 civilians were still trapped there.

* Asked if Russia would rule out a pre-emptive tactical nuclear strike on Ukraine, Russia's deputy foreign minister said the option was clearly set out in its military doctrine, RIA reported.

DIPLOMACY AND SANCTIONS

* The US House of Representatives approved more than $US40 billion ($A58 billion) more aid for Ukraine as Congress races to keep military aid flowing and boost the government in Kyiv.

* President Joe Biden's nominee to be the next ambassador to Ukraine, veteran diplomat Bridget Brink, was expected to easily win confirmation to a crucial position that has been vacant for three years after a smooth confirmation hearing.

* Foreign Minister Annalena Baerbock, the highest-ranking German government official to visit Ukraine since Russia's invasion began on February 24, announced the reopening of the German embassy in Kyiv and said Ukraine should become a full EU members at some point.

HUMAN TOLL

* Thousands more civilians have been killed in Ukraine than the official toll of 3381, the head of the United Nation's human rights monitoring mission said.

* More than eight million people had been displaced inside Ukraine since the start of the invasion, the UN migration agency said.

Australian Associated Press