Finland's President Alexander Stubb has called for expansion of the U.N. Security Council, abolition of its single state veto power, and suspension of any member engaging in an "illegal war" such as Russia's invasion of Ukraine.

Stubb, who leads the Nordic nation's foreign policy, said he would add his voice to reform calls at next week's U.N. General Assembly in New York which is to discuss composition of the global body's Security Council.

Consisting of five permanent and 10 rotating member states, the council's brief is to keep global peace, but geopolitical rivalries have deadlocked it on issues from Ukraine to Gaza.

Stubb said in an interview on Tuesday he would propose the number of permanent members be expanded from five to 10, with one more from Latin America, two from Africa and two from Asia.

"No single state should have veto power in the U.N. Security Council," he told Reuters.

The U.S., one of five veto-wielding nations with Russia, China, France and Britain, has also backed two permanent seats for Africa.

Stubb said any member engaging an illegal war, "such as Russia is in right now in Ukraine", should be kicked off.

Moscow has justified its invasion of Ukraine by saying it is creating a buffer against Western aggression and taking territory that is historically Russia's.