"If we resolve as a whole the questions of abductions of Japanese citizens (and) the missile and nuclear problem, we manage to draw a line under the unhappy past and normalise diplomatic relations, then we can provide it (North Korea) with economic aid," Abe said in translated comments to journalists after meeting Russian President Vladimir Putin in the far eastern city of Vladivostok.

Japan, which has remained on the sidelines during a recent flurry of diplomatic activity over North Korea, sees it as particularly important to discuss with Pyongyang the scores of Japanese citizens kidnapped by the isolated state in the 1970s and 1980s to help train its spies.

In a televised interview in June, Abe expressed a readiness to finance denuclearisation costs in North Korea.

He called on North Korean leader Kim Jong Un to help overcome their mutual distrust, as he confirmed efforts were ongoing to arrange a Japan-North Korea summit, which has not materialised.

Japan takes a harsh stance towards Pyongyang, which has sent numerous missile tests in the direction of its territory.

Japan's defence ministry in a report last month said North Korea still poses a "serious and imminent threat" despite a diplomatic détente earlier this year.

Nuclear-armed North Korea will be among the issues topping the agenda as Russia's Vladimir Putin holds meetings with Asian leaders in Vladivostok this week on the sidelines of an economic forum.

Putin is set to meet Chinese President Xi Jinping on Tuesday and South Korea's Prime Minister Lee Nak-yeon on Wednesday.

In recent months Putin has kept his distance from the dramatic rapprochement between Trump and Kim Jong Un that culminated in a historic summit on June 12, which has however struggled to translate into concrete progress on the promised denuclearisation.

Putin has invited the North Korean leader to make his first ever visit to Russia, but Kim has never responded.

A North Korean delegation headed by minister of External Economic Relations Kim Yong Jae on Monday headed to Vladivostok to take part in the forum.