The planned visit comes as the United States has pressed North Korea to give up its nuclear weapons program. Last year, Washington imposed the most biting sanctions ever on Iran following its exit from a 2015 nuclear agreement with Iran and five major world powers.

North Korean Foreign Minister Ri Yong-ho visited Iran in August last year and met with Iranian President Hassan Rouhani and Zarif.

North Korea and Iran have been suspected of exchanging missile parts and technology, especially during the 1980-1988 Iran-Iraq war.

In 2006, Iran's military commander publicly acknowledged that his country obtained Scud-B and Scud-C missiles from North Korea during the war, but said Tehran no longer needs foreign assistance.

(Yonhap)