Japan and Australia agreed Wednesday to keep up pressure on North Korea to denuclearize through the strict enforcement of U.N. sanctions on Pyongyang, despite easing tensions over its arms development program.

The foreign and defense ministers of the two countries, in their talks in Sydney, also acknowledged the need to strengthen defense ties, including increasing joint exercises by their armed forces, amid a rapidly changing security environment in the region.

(From left, Australian Defense Minister Christopher Pyne, Foreign Minister Marise Payne and her Japanese counterpart Taro Kono and Defense Minister Takeshi Iwaya)

The ministers welcomed North Korea's diplomatic engagement started this year with South Korea and the United States, which has led to Pyongyang's commitment to "complete" denuclearization.

But they regarded it as too early to relax the sanctions under relevant U.N. Security Council resolutions that were imposed following a series of nuclear and ballistic missile tests, given that North Korea has yet to take any concrete action to abandon its weapons program.

Australian Foreign Minister Marise Payne, speaking at a joint press conference following the meeting, said both sides agreed to "maintain pressure" on North Korea and that they "need to see real steps to complete, verifiable (and) irreversible denuclearization of the (Korean) Peninsula."

"It continues to be important for the international community to be united in fulfilling the resolutions," Japanese Foreign Minister Taro Kono said. "When doing so, there must be no loopholes."

Kono and Japanese Defense Minister Takeshi Iwaya said they agreed to work closely with their Australian counterparts Payne and Christopher Pyne, to prevent North Korea from evading the sanctions through illegal ship-to-ship transfers of refined petroleum products and other goods at sea.

During the talks, known as "two-plus-two," they also confirmed to work toward an early conclusion of a visiting forces agreement, which will enable the two countries to conduct joint military drills and disaster relief operations more smoothly.

In a joint statement, the ministers said they are determined to explore opportunities to broaden areas of defense force drills and added they plan a first-ever fighter jet exercise, dubbed "Bushido Guardian," in 2019. It was to be held in September but postponed after a deadly earthquake hit the northern Japan prefecture of Hokkaido.

Japan and Australia, which seek to deepen their "special strategic partnership," began negotiating the agreement in 2014. It would be the first such accord for Tokyo after the Japan-U.S. Status of Forces Agreement, which details the legal status of U.S. military personnel stationed in Japan.

Japan views Australia as a "quasi-ally" and is believing that strengthening their relationship in the field of security is becoming more important to promote Prime Minister Shinzo Abe's "Free and Open Indo-Pacific Strategy."

The concept reflects Japan's interest in boosting relations with countries from Asia to as far as Africa that share such universal values as democracy and the rule of law, amid China's rising international clout.

In this respect, the ministers also reaffirmed the importance of promoting trilateral cooperation with the United States to deal with challenges in the Asia-Pacific region, while expressing concern about the situation in the East and South China seas, where China's maritime assertiveness has been growing.

Payne disclosed that the Japanese prime minister will visit the northern Australian city of Darwin in November to hold a high-level bilateral economic dialogue.

For his first talks with Australian Prime Minister Scott Morrison, who took office in late August, Abe is likely to visit Darwin during a trip in mid-November to Singapore and Papua New Guinea to attend annual regional summit meetings.

Abe would be the first Japanese leader to visit Darwin, which the now-defunct Imperial Japanese forces bombed in February 1942, killing over 230 Australians.

Payne and Pyne took up their posts following the inauguration of Morrison, while Iwaya assumed his post after Abe's Cabinet reshuffle on Oct. 2. Kono retained his portfolio.

It is the eighth time for the two countries to hold a two-plus-two meeting since the framework started in 2007. The previous meeting took place in April last year in Japan.