Indonesia on Thursday ordered 42 Rafale fighter jets from France and may acquire two French submarines, while the United States approved Jakarta's potential purchase of 36 F-15s in the face of growing tensions in the Asia-Pacific.

Indonesia's first order for French warplanes comes as Jakarta replaces an ageing fleet -- consisting mainly of American F-16s and Russian Sukhois -- as concerns grow about rising US-China tensions in Asia.

The Rafale agreement was announced as Indonesian Defence Minister Prabowo Subianto met his French counterpart Florence Parly in Jakarta.

Subianto confirmed a deal had been struck for the purchase of the jets, with a contract signed Thursday relating to the first six.

France's defence ministry said the contract for the 42 aircraft and their weapons was worth $8.1 billion (7.1 billion euros).

Spokesman Herve Grandjean said the two countries also signed a letter of intent for research and development with a view to Indonesia ordering two Scorpene submarines.

Meanwhile, the US State Department said it had approved the potential F-15s sale along with other assorted military equipment for an estimated $14 billion.

The proposed sale will improve "the security of an important regional partner that is a force for political stability, and economic progress in the Asia-Pacific region," said a statement, adding that it "will not alter the basic military balance in the region."

It did not mention China, whose rise Washington is seeking to counter in the region, and gave no indication when the sale could be concluded.

The Rafale deal is the latest sign of warming ties between Jakarta and Paris, as France rethinks its alliances in the region following the collapse in September of a multibillion-dollar Australian submarine deal.

Paris was left furious by the debacle, saying it had been given no warning that Canberra was negotiating a new defence pact with the United States and Britain.

Australia is now obtaining nuclear-powered submarines as part of the new defence alliance, named AUKUS, which brings together Canberra, Washington and London to counter a rising China.

French President Emmanuel Macron welcomed Indonesia's decision to choose "French industrial excellence", writing on Twitter that the Rafale deal would "strengthen our partnerships". 

In November, France and Indonesia strengthened a strategic partnership agreement during a two-day visit by French Foreign Minister Jean-Yves Le Drian to the vast Southeast Asian archipelago.

- 'Technical excellence' -
In Jakarta, Parly told reporters that Indonesia had chosen a warplane known for its "technical excellence", which had demonstrated its "operational capabilities on numerous occasions".

Eric Trappier, CEO of manufacturer Dassault Aviation, said the contract "marks the start of a long-term partnership that will see Dassault Aviation rapidly step up its presence in the country.

"It also demonstrates the strong bond between Indonesia and France and reinforces the position of the world's largest archipelago as a key power on the international stage."

The president of ship and submarine manufacturer Naval Group, Pierre-Eric Pommellet, accompanied Parly in Jakarta and signed a memorandum of understanding with Indonesia's PT Pal, according to a source within the French company. 

The agreement included technology transfer, but "everything remains up for negotiation" regarding the Scorpene submarines, the source added.

Scorpenes are conventional diesel-electric attack submarines. They are capable of carrying 18 torpedoes and Exocet anti-ship missiles and navigating to a depth of 350 metres (1,148 feet), according to Naval Group.

Indonesia is also participating in a South Korean programme to develop a warplane.

- Arms race fears -
Since the Australian submarine deal collapsed, France has been bolstering ties with long-time partners including Japan and India, as well as turning to Southeast Asian nations such as Indonesia.

Indonesia is one of several Asian countries that expressed concerns about the AUKUS pact, with Foreign Minister Retno Marsudi warning it could trigger a nuclear arms race in the region. 

The Dassault Aviation Rafale aircraft, which entered service in 2004, has proved popular in the international market despite competition from American and other European manufacturers. 

The United Arab Emirates signed the biggest ever order for the jets in December, with a deal to buy 80 for 14 billion euros. 

Other foreign clients include Qatar, India, Egypt, Greece and Croatia.