Japanese Prime Minister Shinzo Abe reiterated Wednesday his determination to resolve a long-standing territorial dispute with Russia over a group of islands off northern Japan and conclude a postwar peace treaty.

During a speech at a plenary session of a regional economic forum in Vladivostok, Abe said, "Over the long stretch of more than 70 years since the end of World War II, Japan and Russia have yet to conclude a peace treaty between them. President Putin and I agree in our belief that this is an abnormal state of affairs."

Abe held his 22nd summit with Vladimir Putin on Monday, but there was little progress in their negotiations over the Russian-held islands claimed by Japan, which are called the Northern Territories in Japan and the Southern Kurils in Russia.

The islands -- Etorofu, Kunashiri, Shikotan and the Habomai islet group -- were seized by the Soviet Union after Japan surrendered in World War II in August 1945.

(The Kunashiri Island)

Abe urged Putin to move forward the negotiations, saying, "If we don't do it now, then when?" and "If we do not do it, then who will?"

The Japanese leader is eager to advance territorial talks as he is widely projected to win the Sept. 20 leadership race of his ruling party and secure another three-year term as its chief and Japan's prime minister. Putin cemented his political power by securing a six-year term in a presidential election in March.

The annual Eastern Economic Forum has been held since 2015 by Putin for the purpose of drawing more investment to the Russian Far East.

Tokyo is seeking to break the impasse in the territorial row by building trust with Moscow through ongoing economic cooperation in the Russian Far East and planned joint economic activities on the disputed islands.

"Through Japan-Russia cooperation, here, Vladivostok, and locations all around Far East Russia will become gateways where human resources, goods, and capital come together," Abe said.

On North Korea, the Japanese prime minister underlined the necessity of realizing the complete denuclearization of the Korean Peninsula and expressed his hope that the next round of inter-Korean summit talks scheduled for next week in Pyongyang would lead to the North taking concrete action toward that goal.

Abe also pledged to resolve the issue of Japanese nationals abducted by North Korean agents decades ago, which he has made one of his priorities, saying, "I am determined for us to take steps towards settling the unfortunate past with North Korea and normalizing our relations."

"I too must break the shell of mutual distrust, take a step forward, and ultimately meet with Chairman Kim Jong Un," Abe said, referring to the North Korean leader. But he added that nothing has been decided with regard to a possible Japan-North Korean summit.

Following his talks with Chinese President Xi Jinping earlier in the day on the sidelines of the forum, Abe vowed continued efforts to improve bilateral ties.

"In response to China's gracious invitation, I intend to visit China this year, the year in which we commemorate the 40th anniversary of the conclusion of the Treaty of Peace and Friendship between Japan and China," he said.

Promising to invite Xi to Japan afterward, the prime minister said he hopes to "raise Japan-China relations to a new stage."

Besides Abe, Putin and Xi, South Korean Prime Minister Lee Nak Yon and Mongolian President Khaltmaa Battulga also attended the plenary session of the annual event.