TOKYO — Japan launched its new space defense unit Monday to monitor and counter threats to the country’s satellites.

The Space Operations Squadron, part of the Japan Air Self-Defense Force, starts with 20 members and is expected to grow to about 100 members once the unit is fully operational in 2023.

The role of the unit is mainly to monitor and protect Japanese satellites from enemy attacks or space debris. It will also conduct satellite-based navigation and communications for other troops in the field.

The launch of the new unit comes amid growing Japanese concern that China and Russia are seeking ways to interfere, disable or destroy satellites.

The unit will cooperate with U.S. Space Command that President Donald Trump established last year, as well as Japan’s space exploration agency, Japan Aerospace Exploration Agency, Defense Minister Taro Kono said.

“It is important that we gain superiority in the space domain as well,” Kono said Monday at a launch ceremony. “We must adapt to the new security environment as soon as possible.”

Prime Minister Shinzo Abe has pushed for Japan’s Self-Defense Force to expand its international role and capability by bolstering cooperation and weapons compatibility with the U.S., as it increasingly works alongside American troops and as it grows concerned about the increasing capabilities of China and North Korea.