"File for the appointment of India's first CDS was cleared by Appointment Committee of Cabinet headed by Prime Minister Narendra Modi on Monday morning," said a senior government officer, privy to the decision making process.

The government announced that Gen Rawat, who is all set to demit office as army chief on Tuesday, has been appointed as CDS with effect from Tuesday itself and will be holding the post till 65 years of age, which for him is March 31, 2023.

General Rawat had served a rare full three year term as the Indian Army Chief after he superseded two officers in 2016.

He was commissioned into the 11 Gorkha Rifles on December 16, 1978.

On Sunday, the Defence Ministry amended the Indian Army, Indian Navy and Indian Air Force rules, to provide for the CDS or tri-service chiefs being able to serve till 65. As per existing government rules, the three service chiefs can serve up to the age of 62 or for three years, whichever is earlier.

In his Independence Day speech this year, Prime Minister Narendra Modi had announced that India will have the CDS. The Union Cabinet had, on December 24, approved the post of the CDS and its charter and duties. The CDS will be a 4-star general rank officer.

"He will be drawing a salary equivalent to service chiefs, and will head the Department of Military Affairs to be created under the Ministry of Defence. He will function as its Secretary," Union Minister Prakash Javadekar said during the Cabinet briefing.

The CDS will have all the powers like other secretaries, including financial.

Defence Minister Rajnath Singh had hailed the Union Cabinet's approval for the CDS and its charter and duties, calling it an "historic and major" decision towards bringing about jointmanship between the armed forces.

The CDS will act as the Principal Military Adviser to the Defence Minister on tri-services matters. The three service chiefs will continue to advise the Defence Minister on matters exclusively concerning their respective forces.

The idea of creating the CDS' post is that India should not have a fragmented approach. "Our entire military power will have to work in unison. All the three (services) should move simultaneously at the same pace," said a senior government official.

The CDS was planned after looking into the changing nature of warfare, security environment and national security challenges.

The biggest challenge before CDS will be to ensure jointmanship among the three services which will include powers to work on setting up of few theatre commands as well as to allocate military assets among the services to synergise their operations.