South Korea's defense ministry has said there remains a possibility of North Korean leader Kim Jong-un traveling to Russia for summit talks with Russian President Vladimir Putin.

Spokesperson Jeon Ha-kyu said on Monday that the ministry assesses there is a chance that Kim may still visit Russia, and discussions for such a meeting are in progress.

Last week, The New York Times reported, citing U.S. government officials, that Kim and Putin could meet to discuss an arms trade on the margins of the Eastern Economic Forum(EEF) in Russia's Vladivostok, scheduled between Sunday and Wednesday.

Japanese public broadcaster NHK also reported that the North Korean leader was speculated to depart for Russia via his personal train on Monday.

However, there has been no official announcement from Pyongyang or Moscow.

Russia's Interfax news agency reported on Putin's official schedule at the EEF from Monday through Tuesday, but it did not include a meeting with Kim.

Meanwhile, an Air Koryo flight, initially scheduled to depart from Pyongyang and land in Vladivostok at 11:15 a.m. on Monday, was canceled. The sudden change of schedule has raised speculation that it may be related to Kim's potential visit.