Japanese Prime Minister Shinzo Abe said Friday that he and Russian President Vladimir Putin agreed to strictly implement U.N. sanctions on North Korea and continue cooperating closely in trying to halt its nuclear program.

Just after holding a meeting with Putin in the Vietnamese coastal city of Danang, Abe also told reporters that they agreed to accelerate the pace of preparations for joint economic programs to be carried out on islands disputed between the two countries.

Putin said he is "very pleased" that ties between the two countries are "steadily developing," backed by active political dialogue and progress on economic cooperation, as they sat together for the talks, which lasted about an hour.

A senior Japanese government official told reporters that the two leaders held a separate 15-minute conversation, only accompanied by their interpreters, which mainly focused on issues related to the Russia-controlled islands.

But the official declined to disclose the specifics of their discussions.

The meeting, the 20th between the two leaders, on the sidelines of a regional summit came just days after the prime minister and U.S. President Donald Trump agreed to maximize pressure on North Korea until it changes its nuclear and missile policies.

At Monday's formal meeting in Tokyo between Abe and Trump, the two leaders agreed that more cooperation from China and Russia is needed to rein in North Korea.

North Korea has halted a high-profile arms test for nearly two months, but it has not shown any sign of relenting in its quest to develop a nuclear-tipped intercontinental ballistic missile.

Meeting before the opening of the Asia-Pacific Economic Cooperation forum summit, Abe told Putin that he wanted to discuss steps toward the denuclearization of the Korean Peninsula.

Still, China and Russia, two of the five veto-wielding permanent members of the U.N. Security Council, have diplomatic and economic ties with North Korea, and they are traditionally reluctant to push Pyongyang too much into a corner.

Abe asked Putin that Russia play a "larger role" in addressing the North Korean nuclear issue, according to the official, Deputy Chief Cabinet Secretary Kotaro Nogami, who attended the meeting and provided a briefing on some of its outcome.

When Abe and Putin last held talks in September in the Russian Far East city of Vladivostok, besides exchanging views over North Korea, both sides agreed to designate five candidate areas for the projects and agreed to undertake each of them as quickly as possible.

Abe said this time they agreed to speed up preparations "toward next spring" for the implementation of the five project areas.

Abe is planning to visit Russia in May next year. Japan is seeking tangible progress on the projects as soon as possible and both sides agreed to organize a meeting of senior officials early last year.

The five areas included aquaculture and wind power. While Russia is eager to develop its Far East region, Japan hopes that carrying out those projects will pave the way toward a settlement of the long-running dispute.

The dispute over Etorofu, Kunashiri and Shikotan islands and the Habomai group of islets, seized by the Soviet Union in 1945 after Japan's surrender in World War II, has prevented the two countries from signing a postwar peace treaty.

They are known in Japan as the Northern Territories and in Russia as the Southern Kurils.

As special grave visits by airplane to the islands by former Japanese residents materialized in September for the first time, Abe and Putin agreed to explore more measures for freer entry and exit by them.