The United States and Japan on Wednesday announced stepped-up security cooperation in the face of shared worries about China, and Washington strongly endorsed a major military buildup Tokyo announced last month, Reuters reported.

A joint statement issued after a meeting between their foreign and defense ministers in Washington said the two countries "provided a vision of a modernized Alliance postured to prevail in a new era of strategic competition."

"We agree that the PRC is the greatest shared strategic challenge that we and our allies and partners face," U.S. Secretary of State Antony Blinken told a joint news conference after the meeting, referring to the People's Republic of China.

At the briefing, U.S. Defense Secretary Lloyd Austin announced plans to introduce a Marine Littoral Regiment in Japan, which would bring significant capabilities, including anti-ship missiles.

Blinken said that two sides also agreed to extend the terms of their common defense treaty to cover space.

Austin is to meet Japanese Defense Minister Yasukazu Hamada again on Thursday at the Pentagon ahead of a meeting between U.S. President Joe Biden and Japanese Prime Minister Fumio Kishida on Friday.

The agreement follows nearly a year of talks and comes after Japan last month announced its biggest military build-up since World War Two.

That five-year plan will double Japan's defense spending to 2% of its gross domestic product and see it procure missiles that can strike ships or land-based targets 1,000 km (600 miles) away.

The anti-ship missiles will arrive in Japan under a revamped Marine Corps regiment of 2,000 troops that will focus on advanced intelligence, surveillance and transportation, US officials told Reuters. The move is expected to be completed by 2025.

The officials added that a separate U.S. Army company of about 300 soldiers and 13 vessels would be deployed by this spring to help transport U.S. and Japanese troops and equipment, allowing for the rapid dispersal of forces.