The commander of US forces in the Middle East, Gen. Joseph Votel (above), said that thus far the Americans have made do with providing support to local armed groups

The United States could be sending more troops to Syria in order to accelerate the campaign against Islamic State, military officials said on Wednesday.

The Americans are mulling 'taking on a larger burden ourselves' in the bid to unseat ISIS from its de-facto capital, Raqqa, according to CBS News.

The commander of US forces in the Middle East, Gen. Joseph Votel, said that thus far the Americans have made do with providing support to local armed groups tasked with fighting the jihadist organization.

But given the limitations of these groups, Votel said that his forces could play a more active role on the battlefield.

The local forces being backed by the US in Syria 'don't have as good mobility, they don't have as much firepower, so we have to be prepared to fill in some of these gaps for them and that may involve additional fire support capability, a variety of other things that we bring in to help offset some of the gaps that they have and we take the burden on ourselves for that aspect of the fight,' Votel told CBS News.

The Pentagon is expected to present President Donald Trump with a plan for a speedy defeat of ISIS.

In his campaign for president, defeating ISIS was a major theme for Trump, who vowed to wipe out the group 'from the face of the earth.'

A statement on the White House website said: 'Defeating ISIS and other radical Islamic terror groups will be our highest priority. To defeat and destroy these groups, we will pursue aggressive joint and coalition military operations when necessary.'

While the US military insists that it will continue to enact Barack Obama's policy of having local allies in the lead, Votel said that the high command was 'very concerned about maintaining momentum.'

A member loyal to ISIS waves the group's flag in Raqqa in this June 29, 2014 file photo. The US wants to unseat ISIS from Raqqa, its de-facto capital in northern Syria

Members of the US-backed Syrian Democratic Forces, a group comprised of Arab and Kurdish fighters, are seen above as they make their way toward ISIS' de-facto capital of Raqqa in northern Syria

The Americans are apparently not willing to wait through the time-consuming process of training a sufficient number of local Arab fighters to finish the job.

The US may soon shift to a strategy similar to the one currently in place in Iraq – increased logistical support as well as artillery fire cover.

One of Votel's subordinates, Lt. Gen. Steve Townsend, said recently that he believed ISIS would be routed in both Raqqa and the Iraqi town of Mosul within six months.

The recapture of Mosul would deal a death blow to the 'caliphate' which ISIS chief Abu Bakr al-Baghdadi proclaimed in the city in June 2014 but has been shrinking steadily for two years as anti-IS forces advanced.

US-backed Iraqi forces closing in on the Islamic State-held western half of Mosul prepared on Tuesday to storm the airport and a nearby military base on its southern outskirts to create a bridgehead for a thrust into the city.

Since ousting the militant group from eastern Mosul last month, Iraqi forces have advanced in sparsely populated outlying areas but fighting will intensify as they near the teeming inner city of western Mosul and the risk to roughly 750,000 civilians there will rise.

Members of the Iraqi federal police react as they arrive in Albu Saif, which was recently retaken by Iraqi military forces, south of Mosul, on Wednesday

Iraqi federal police and elite interior ministry units known as Rapid Response have made rapid progress towards western Mosul in a sweep from the south through stony desert terrain since launching the offensive's second phase on Sunday.

After fighting their way with helicopter gunships, machine gun fire and rocket-propelled grenades to Albu Saif on Monday, Iraqi forces were building up their positions in the hilltop village that overlooks the airport and built-up western Mosul beyond, a Reuters correspondent reported from the area.

The corpse of an Islamic State insurgent with a missing leg lay in the street of Albu Saif village.

Iraqi forces reached the 'vicinity' of Mosul's international airport on Monday, the military said.

A Rapid Response spokesman said the airport, once retaken, would be a close-support base for the onslaught into the west of Iraq's second-largest city.

Iraqi forces will also need to secure the Gozhlani military complex, which includes barracks and training grounds and sprawls across the area between the airport and the end of the Baghdad-Mosul highway.