US President Joe Biden and Japanese Prime Minister Fumio Kishida will likely further discuss the topic when they meet in Washington on Wednesday, a source with knowledge of the talks said.
Japan's first potential inclusion was first reported by The Financial Times over the weekend, but was confirmed by AUKUS members on Monday.
AUKUS, formed by the three countries in 2021, is part of efforts to push back against China's growing power in the Indo-Pacific region.
Its first pillar is designed to deliver nuclear-powered attack submarines to Australia. The statement did not propose Japan would be involved in this part of the pact.
However, a second pillar is focused on delivering advanced capabilities and sharing technologies across a range of areas including quantum computing, undersea, hypersonic, artificial intelligence and cyber technology.
"Recognising Japan's strengths and its close bilateral defence partnerships with all three countries we are considering cooperation with Japan on AUKUS Pillar II advanced capability projects," the statement, published by the British government, said.
The statement said AUKUS members had long been clear on their intent to involve other countries in Pillar II, and that it would take into account factors such as: "Technological innovation, financing, industrial strengths, ability to adequately protect sensitive data and information, and impact on promoting peace and stability in the Indo-Pacific region".
China has called the AUKUS pact dangerous and warned it could spur a regional arms race.
Japanese Chief Cabinet Secretary Yoshimasa Hayashi said earlier that nothing had been decided about cooperation with AUKUS at the moment.
