US vows to 'hunt down' last IS fighters, as group's defeat nears

The last Islamic State group fighters will be "hunted down", US vice-President Mike Pence vowed on Saturday, as the group's enclave in Syria shrinks to a scrap of land in the east of the country.

"The United States will continue to work with all our allies to hunt down the remnants of [IS] wherever and whenever they rear their ugly heads," Pence said.

It comes as IS' last territories in Syria shrinks to just over half-kilometres of land around a Deir az-Zour village, according to the Syrian Democratic Forces (SDF).

"IS is besieged in a neighbourhood that is estimated to be 700 metres long and 700 metres wide" in the village of Baghouz, said SDF commander Jia Furat.

"Baghouz is within our firing range but we are moving cautiously considering there are civilians still trapped there as human shields."

The offensive on IS has been nearing completion for weeks, but the SDF commander said the operation was paced down this week due to the high number of civilians who remain in the area, but it will soon be completed.

"In a very short time, not longer than a few days, we will officially announce the end of IS' existence," he added, according to AFP.

The SDF had paused the offensive over the past weeks to allow civilians to escape with thousands taking advantage of this window, although there are still civilians inside the last IS territory "in large numbers", according to an SDF spokesperson.

"We weren't expecting this number, otherwise we wouldn't have resumed the campaign four days ago. This is why it's been delayed," SDF spokesman Adnan Afrin said.

US President Donald Trump said on Friday afternoon UK time that he expected the defeat of IS within 24 hours.

Human rights groups have urged Trump not to accelerate the offensive in order to protect civilians inside Baghouz, where tunnels and improvised bombs have also slowed the SDF advance.

"The tempo of battle must not be dictated by political imperatives - it must first of all protect civilians and possible hostages," HRW's director of counterterrorism, Nadim Houry, told AFP.

IS once controlled much of eastern Syria and northern Iraq, until separate US-backed offensives against the group by the SDF and Baghdad pushed them back.

Bashar al-Assad's regime and Syrian rebels have also fought IS, although there are fears that a swift US pull-out of Syria could lead to a new insurgency.

German Chancellor Angela Merkel also warned on Saturday that a US pull-out risks allowing Russia and Iran to boost their role in Syria.

Both countries are key allies of Bashar al-Assad's regime, and have played a huge role in the government's fight-back against rebels.

"Is it a good idea for the Americans to suddenly and quickly withdraw from Syria? Or will it once more strengthen the capacity of Iran and Russia to exert their influence?" she said at a security conference in Munich, also attended by Pence.

Agencies contributed to this story.