The U.S. State Department has approved the sale of mobile rocket launchers to Australia, as the country seeks to boost its military presence in the Indo-Pacific region.

The U.S. approved several weapons sales worth as much as $3.1 billion to allies, the Pentagon said on Tuesday, including helicopters to Egypt and missiles to the Netherlands.

Australia has been boosting its defense spending over the past few years as China looks to step up its presence in the Indo-Pacific region. Last year, Australia entered into a deal to buy nuclear submarines from the United States and Britain.

The sale to Australia of High Mobility Artillery Rocket Systems (HIMARS) launchers and related equipment will cost an estimated $385 million.

Australia requested to buy 20 HIMARS and other equipment, the Pentagon said. The principal contractors will be Lockheed Martin, L3Harris Corp and Chelton Inc, it said.

Approval by the State Department at this point virtually ensures the sales will go through.

The U.S. also approved the sale of CH-47F Chinook helicopters and related equipment to Egypt for an estimated cost of $2.6 billion.

Egypt requested to buy 23 CH-47F Chinook helicopters, the Pentagon said, adding that the principal contractor will be Boeing Helicopter Co..

The Netherlands increased a previous order for AIM-9X Block II Tactical Missiles and AIM-9X Block II+ Tactical Missiles. The missiles will be made by Raytheon and have a total approximate value of $117 million, the Pentagon said.

The Pentagon's Defense Security Cooperation Agency notified Congress of the possible sale on Thursday.