Leaders from the Quad grouping -- Japan, the United States, Australia and India -- are set to gather on Tuesday for a roughly two-hour summit on regional security.

One of the key topics is what the leaders call "a free and open Indo-Pacific," where China has been increasing its military activities.

The meeting comes a day after Japanese Prime Minister Kishida Fumio and US President Joe Biden held bilateral talks dominated by China-related issues.

China was at the focus of talks between Kishida and Biden on Monday. The joint statement from Japan and the US said they have renewed their commitment to strengthening deterrence and their response capabilities.

The leaders of India and Australia will join them at this summit, and they are expected to agree on advancing a free and open Indo-Pacific.

They are also expected to discuss Russia's invasion of Ukraine.

In their talks, the Quad leaders will agree that unilateral changes to the status quo by force are unacceptable anywhere in the world. This could serve as a warning to China regarding Taiwan.

The leaders will also talk about North Korea and its repeated missile tests.

This past week, the US warned that Pyongyang could launch a missile or conduct a nuclear test during Biden's visit.

The Quad leaders are expected to agree on the need to denuclearize the Korean Peninsula.

Later in the day the four leaders will release a joint statement, and Kishida will hold a news conference.