The five Nordic countries have told Ukrainian President Volodymyr Zelenskiy during talks in Oslo that they will support Ukraine "for as long as it takes" in its struggle to drive out Russian forces.
Zelenskiy made his surprise visit to the Norwegian capital after meeting US President Joe Biden and lawmakers in Washington DC on Tuesday to plead for more military aid in the face of scepticism from key US Republicans.
Together, Norway, Sweden, Denmark, Finland and Iceland have provided aid to Ukraine worth 11 billion euros ($A18 billion) since Russia invaded in February 2022 and are ready to continue giving extensive military, economic and humanitarian support, the five countries said in a joint statement.
"The Nordic countries will stand with Ukraine for as long as it takes... Russia must end its aggression and withdraw its forces immediately and unconditionally from the territory of Ukraine within its internationally recognised borders," it said.
Separately, Danish Prime Minister Mette Frederiksen said her government would present a new support package for Ukraine worth 1 billion euros to parliament this week.
Four of the five Nordic countries are members of NATO, and Sweden is waiting for its application to join to be approved by all 31 member states.
Zelenskiy earlier stressed the importance of bolstering Ukraine's air defences, after Russia struck the Ukrainian capital Kyiv with ballistic missiles overnight in the second such attack so far this week.
"Today we talked, and will talk, about such specific things that can save thousands and thousands of Ukrainian lives, as well as increasing pressure on the aggressor," he told a joint news conference with Norway's Prime Minister Jonas Gahr Stoere.
Stoere said Norway would donate 3 billion crowns ($A410 million) to Ukraine, part of a package approved previously by Norway's parliament, of 75 billion crowns over five years.
"We are providing targeted, long-term support to assist Ukraine in its battle for freedom and democracy," Stoere said in a statement.