President Sauli Niinisto said Thursday that Finland would address all concerns addressed by Turkey on its NATO bid and condemned "terrorism" -- a key issue raised by Ankara.

"We condemn terrorism in all its forms and we are actively engaged in combating it," Niinisto told reporters next to President Joe Biden who strongly backed NATO bids by both Finland and Sweden.

"We are open to discussing all the concerns that you may have concerning our membership in an open and constructive manner," Niinisto said, addressing Turkey -- which has accused the Nordic nations of harboring terror groups including outlawed Kurdish militants.