Paris, Nov 18 (IANS): French presidential candidate Alain Juppe has pledged "a merciless war" to uproot Islamic State (IS) insurgents in Iraq and Syria, adding the option of sending French ground troops to the region is not on his agenda.

Speaking about the country's participation in the US-led military operation in Iraq and Syria, the conservative politician said "the fight against the IS for me is an absolute priority", Xinhua news agency reported on Friday.

"I will be committed with our allies to eradicate those who threaten us," he said.

If elected, Juppe said he would help to consolidate the coalition's offensive but refused to send French ground troops, arguing "it is up to the countries of the region to do this work".

Asked about the role of Syrian President Bashar al-Assad in an eventual peace deal, the moderate conservative saw "no return to peace in Syria while al-Assad is in power".

The country's pollsters showed Juppe, 71, winning the first round of the primary by between 36 and 39 per cent, outpacing his challenger ex-president Nicolas Sarkozy.