TOKYO, October 11. /TASS/. Russia and the United States, being nuclear powers, should hold a direct dialogue on the situation in Ukraine, Director General of the Russian Council on International Affairs Andrey Kortunov said in an interview with Japan’s NHK TV Channel whose excerpts were published on Tuesday.

"This is primarily a problem between Russia and the United States, which are nuclear super-powers and, therefore, some kind of consultations or contact is needed," the TV Channel quoted the expert as saying.

Russian leadership is concerned over the West’s mounting military support for Ukraine, Kortunov stressed.

"The nuclear threat will increase, if NATO takes a more direct and large-scale part in the Ukraine conflict," the Japanese TV Channel quoted the expert as saying.

"Relying on Russian legislation, it can be said that the war is directly taking place on the territory of the Russian Federation. The war is ongoing not only with Ukraine’s participation but with the active involvement of a whole slew of Western countries, including those that possess nuclear weapons," Kortunov pointed out, commenting on the developments after the accession of the Donetsk and Lugansk People’s Republics, the Zaporozhye and Kherson Regions to Russia.

From September 23 to September 27, the Donetsk and Lugansk People’s Republics (DPR and LPR) as well as the Kherson Region and the Zaporozhye Region held a referendum where the majority of voters opted to join Russia.

On September 30, Russian President Vladimir Putin and the heads of the DPR and the LPR, the Zaporozhye and Kherson Regions signed treaties on their accession to Russia. On October 4, President Putin signed laws on the ratification of the treaties on accepting the Donetsk and Lugansk People’s Republics, the Zaporozhye and Kherson Regions into Russia.

Russian President Putin said in a televised address on February 24 that in response to a request by the heads of the Donbass republics he had made a decision to carry out a special military operation in Ukraine. The Russian leader stressed that Moscow had no plans of occupying Ukrainian territories, noting that the operation was aimed at the denazification and demilitarization of Ukraine.