Japanese Prime Minister Shinzo Abe sought support from Mongolia on Saturday in Tokyo's territorial row with Beijing over disputed East China Sea islands, during a visit to the country.

Abe arrived in the Mongolian capital Ulan Bator seeking closer trade and diplomatic ties with the mineral-rich nation, a potentially important strategic partner due to its location on China's northern border and diplomatic ties with North Korea.

"I asked for Mongolian support relating to the Chinese situation and Mongolia expressed its understanding of the Japanese position," Abe said in response to questions from journalists about the islands Japan claims as the Senkakus and China as the Diaoyus.

"I understand the Mongolian situation regarding this issue," he added, at a press conference which followed meetings with Mongolian President Tsakhia Elbegdorj and Prime Minister Norov Altankhuyag.

Japan's hawkish leader, who has not held summit meetings with Chinese leaders since he took power in December, also said "the door is open for talks" with China.

On the first of his two-day visit, Abe also discussed North Korea's nuclear ambitions with Mongolia. Pyongyang on Saturday declared it was in a "state of war" with South Korea, warning Seoul and Washington that any provocation would swiftly escalate into an all-out nuclear conflict.

The provocative language follows weeks of dire-sounding pronouncements from the North that have fuelled international concerns that the situation might spiral out of control.

"I explained the Japanese position that the North Korean actions are provocation and we never accept them," Abe said.

During the visit, the first by a Japanese prime minister to Mongolia in nearly seven years, Abe is also aiming to develop closer economic ties with the country.

"During the talks I specifically mentioned expanding economic relations between the two countries," Abe said.

Mongolia has huge mineral deposits at its disposal, and Japan is aiming to secure more fuel resources abroad after its atomic power plans were affected following the Fukushima nuclear crisis, triggered by an earthquake and tsunami in March 2011.

"As Mongolia is rich in natural resources, Japan's technological cooperation will lead to a win-win for both countries," Abe said, according to Kyodo news agency.

China is Mongolia's leading trade partner and source of foreign investment.