TOKYO -- Japan will propose a top-level dialogue with the U.S., India and Australia, Japanese Foreign Minister Taro Kono told The Nikkei on Wednesday. The idea is for the leaders of the four nations to promote free trade and defense cooperation across a stretch of ocean from the South China Sea, across the Indian Ocean and all the way to Africa.

The proposition would be aimed at counteracting China's aggressive maritime expansion under its Belt and Road initiative. China's plans would cement a sphere of influence for Beijing well beyond Asia.

Kono revealed that he exchanged his thoughts on the four-party dialogue with U.S. Secretary of State Rex Tillerson and Australian Foreign Minister Julie Bishop back in August on the sidelines of a foreign ministers meeting in Manila.

Kono also said he offered the foreign ministers of the U.K. and France collaborative roles in the partnership.

Prime Minister Shinzo Abe will officially propose the dialogue partnership to U.S. President Donald Trump on Nov. 6, Kono said.

"We are in an era when Japan has to exert itself diplomatically by drawing a big strategic picture," Kono said during the exclusive interview.

The idea is taking shape as China shakes up its leadership -- an overhaul that could have huge global implications. The Chinese Communist Party on Wednesday announced the new lineup for its seven-member Politburo Standing Committee, Beijing's top decision-making body. Experts say the new committee will give Xi Jinping a stronger grip on power.

Kono said the purpose of the dialogue is to secure a peaceful maritime zone from Asia to Africa. "Free and open seas will benefit all countries, including China and its Belt and Road initiative," the foreign minister said.

Japan expects to play a key role not only among the dialogue partners and collaborators, but also in ensuring freedom of navigation in bodies of water that include the South China Sea, in which China has been building a military presence.

Regarding North Korea's continuing nuclear and missile development, Kono said that having the rogue state completely, verifiably and irreversibly dismantle its nuclear capabilities is "one of the goals." Pyongyang must be brought to the point where it seeks a guarantee that economic sanctions will be lifted if it gives up its nuclear program, Kono said.

For that to happen, North Korea must first change its way of thinking, and "pressure will certainly be necessary" to make it do so, said the foreign minister.

Kono said conditions for talks would include Pyongyang plainly stating its intentions and acting correspondingly. As to what such actions might look like, he suggested that should inspections of the nuclear program become a possibility, accepting a review by the International Atomic Energy Agency would be "the most trustworthy" option.

Kono sees the possibility of the North completing relatively soon an intercontinental ballistic missile capable of striking the American mainland. But should it fire at the U.S., the missile would pass through Russian airspace, which should make the issue difficult for Moscow to ignore, he noted. Kono said it is important to bring China and Russia into closer partnership with Japan, South Korea and the U.S. on the problem.

Asked about Japan's political landscape after Abe, Kono said he had certain goals he was looking to accomplish if he were to become prime minister. But he equivocated as to whether he would throw his hat into the ring for presidency of the ruling Liberal Democratic Party in 2018, saying only that he did not know "what will happen or where" and would have to decide one moment at a time.

Nikkei staff writer Masayuki Yuda contributed to this article.