NEW DELHI (AFP) - India, the world's third largest greenhouse gas emitter, will ratify the Paris climate change pact next month, Prime Minister Narendra Modi said Sunday, bringing the deal a step closer to reality.

Modi said India will formally join the landmark accord struck in 2015 in Paris, through which countries commit to take action to stem the planet's rising temperatures.

The accord needs ratification from 55 countries that account for at least 55 percent of the planet's greenhouse gas emissions responsible for climate change.

"Ratification is yet to be done and India too is yet to do it. I announce that India will ratify the decision on Oct 2, the birth anniversary of Mahatma Gandhi," Modi said in a speech at a national meeting of his ruling party in the southern state of Kerala.

Modi said he had chosen that date because Indian independence leader Gandhi had lived his life with a low carbon footprint.

The treaty moved closer to taking effect earlier this month when a string of countries joined during the UN General Assembly.

UN Secretary-General Ban Ki-moon voiced confidence then that the accord would come into force by the end of the year.

China and the United States, the two largest emitters, gave a major boost to the accord when they signed on during a summit earlier this month between presidents Xi Jinping and Barack Obama.

After a meeting days later with Obama in Vientiane, Modi said India would formally join the agreement later this year.

India has not agreed to cap or cut its carbon emissions outright like some countries.

Instead it says it will hike its use of green energy and reduce its emissions relative to its gross domestic product by up to 35 per cent by 2030 from 2005 levels - meaning emissions will continue to grow but at a slower rate.

India, which relies heavily on coal-fired power plants for electricity, argues that stricter emissions targets would compromise efforts to boost living standards of more than a quarter of its 1.2 billion population which lives in poverty.