Russia kicked off an economic forum in Vladivostok on Sunday, but there was no word from both Moscow and Pyongyang on a possible visit by North Korean leader Kim Jong-un for a meeting with Russian President Vladimir Putin on the sidelines of the forum.

The New York Times earlier reported that Kim may travel to Vladivostok on his armored train to meet with Putin on the margins of the Eastern Economic Forum, which will run through Wednesday at the Far Eastern Federal University.

The report on the possible summit, which would mark their first meeting in four years, came amid speculation North Korea may supply arms for Russia's use in its war in Ukraine in return for food, energy and advanced technology for weapons development.

Sources, however, said unusual signs of Kim's possible trip had not been detected in railway stations in Vladivostok and the border city of Khasan, where his train would likely pass through, as of Sunday morning.

"There have not been any signs of people being deployed to control the railway connecting Khasan and Vladivostok," a source said.

Putin is expected to arrive in Vladivostok on Monday and attend the plenary meeting of the economic forum the following day.

The report on their possible meeting came as Pyongyang has been seeking to bolster military ties with Moscow in the wake of growing security cooperation among South Korea, the United States and Japan following a trilateral summit in Camp David last month.

Seoul's spy agency earlier said Russia had proposed conducting three-way naval exercises with North Korea and China in late July.

Source: Yonhap News Agency