India's new finance minister, Arun Jaitley, has pledged to uphold fiscal discipline, despite mounting pressure on public finances from data showing that the nation is suffering its worst slowdown in over 25 years.

Jaitley, also holding the defence portfolio in Prime Minister Narendra Modi's week-old government, is expected to present his first budget in early July.

In a post on his Facebook page, titled From Celebration to Challenge, Jaitley said pulling India out of the current economic despondency will involve "fiscal rectitude as [a] combination of monetary and fiscal policy".

"Slower GDP growth will imply lower tax buoyancy and [a] higher fiscal deficit," he added. "We must move towards an era of fiscal discipline where we can reduce the fiscal deficit, contain inflation and improve upon our growth rates."

"We must commit ourselves to this discipline... Short term disciplining till we reverse the present trend will give us long term benefits."

Data released on 30 May showed India's economic growth inched up from a decade low in the financial year ended March 2014. However, the reading missed expectations, suggesting the new government faces an uphill task in fixing the nation's economy.

Asia's third largest economy expanded by 4.7% in financial year 2013-14.

The reading came in below the official estimate of 4.9% annual growth and compared with the decade low of 4.5% clocked in fiscal 2012-13.

It marked the second consecutive year of sub-5% growth, resulting in the worst slowdown in more than 25 years.