The Indian air force inducted into service five French-made Rafale fighter jets on Thursday amid heightened tensions with China along their disputed frontier.

New Delhi has sent reinforcements of fighter jets and military equipment to the Ladakh region after the tense standoff there escalated to hand-to-hand combat between Indian and Chinese soldiers on June 15 that left 20 Indians dead.

At the ceremony at a northern airbase, India’s Defence Minister Rajnath Singh said the induction of fighter aircraft was very significant given the security situation at India’s borders. In addition to the standoff in the Ladakh region, Indian troops regularly clash with Pakistani soldiers along the Line of Control.

The fighter jets are part of a $8.78 billion deal signed with France in 2016 as India seeks to modernise its military. All the 36 planes are scheduled to be delivered by 2022 after being made in France.

French Defence Minister Florence Parly, who attended the ceremony, said the Rafale aircraft have proven their capabilities in tackling rebel forces in Mali and Syria. The fully combat-proven ability of the aircraft will “provide an edge to India in the region to protect itself”, she said.

Singh also said that India is now playing play an important role in protecting peace and security in the Indo-Pacific and the Indian Ocean regions.

Later, via a tweet, Singh said that the induction of Rafale "is a strong message for the world and especially for those who challenge India’s sovereignty".

"The induction is a very important step in light of the prevailing security conditions that prevail, or I would say, that have been created along India’s borders."

The first five planes had arrived at the airbase in Ambala in northern Haryana state on July 29. It’s an operational base for Indian forces stationed at the borders with Pakistan and China.

The Rafale have 13 custom features and long-range missiles, providing the Indian air force capabilities like long-range strikes, air defence and interdiction, said defence analyst Rahul Bedi.

The Rafales are the first foreign fighters to join the Indian air force after the Russian Su-30MKI’s were inducted into service in 1997, Bedi said.

India, Japan seal military logistics cooperation pact

Also on Thursday, the Indian defence ministry said in a statement that India and Japan have signed an agreement that will provide their militaries access to each other’s bases for supplies and services.

The two countries have built close defence ties in recent years, which analysts say are part of efforts to counter the growing weight of China across the region.

“The agreement will also enhance the interoperability between the Armed Forces of India and Japan,” the defence ministry statement said.