North Korean leader Kim Jong Un attends celebrations marking the 70th anniversary of North Korea's foundation in Pyongyang, North Korea, in this undated photo released September 10, 2018 by North Korea's Korean Central News Agency (KCNA). KCNA via REUTERS

VLADIVOSTOK, Russia (Reuters) - Russian President Vladimir Putin has sent a letter of invitation to visit Russia to North Korea’s Kim Jong Un, Kremlin aide Yuri Ushakov said on Monday.

He added no detailed plans of a meeting between the two leaders are being discussed at the moment.