Washington (AFP) - The Pentagon will submit proposals to President Barack Obama for strengthening military support to Iraqi forces in the near future, a top US military official said Friday.

"We have a series of recommendations that we will discuss with the president in the coming weeks to further enable our support for the Iraqi security forces," said General Joseph Dunford, chairman of the Joint Chiefs of Staff.

"(Defense Secretary Ashton Carter) and I both believe that there will be an increase in US forces in Iraq in coming weeks, but that decision hasn't been made," Dunford said Friday during a news conference at the Pentagon.

The recommendations will include ways that the US can "enable" Iraqi forces in their efforts to recapture the city of Mosul, the largest urban center in the Islamic State group's "caliphate," an operation that's expected to be long and difficult.

Pentagon officials have previously mentioned their desire to accelerate the training of Iraqi troops, or to provide logistical support for the Mosul offensive.

The US military confirmed this week the presence of some 200 Marines and artillery in northern Iraq, with the artillery used to support Iraqi troops as they advanced in the region.

"There is no inconsistency between what this artillery unit did and what our aviation is doing every single day" in its bombing campaign against IS, he said.

Officially, there are 3,870 US troops deployed in Iraq. But the actual number is likely about 5,000, according to media reports that Dunford did not deny on Friday.

Strengthening US military presence in Iraq is a sensitive issue for the Obama administration, which has vowed not to deploy ground forces there.

Shiite militias in Iraq also oppose additional US deployments to their country.

Dunford and Carter, who was also at the briefing, warned that the battle against IS will play out outside Iraq and Syria as well.

Efforts to prevent attacks such as those carried out in Brussels will not succeed "unless all the countries that are affected by the foreign fighters are cooperating at the law enforcement, the intelligence community level and the military level," Dunford said.

Carter added that these were "critical" components in the fight against IS, especially in European countries.

The United States has repeatedly called on European nations to improve shortcomings in their intelligence sharing and police cooperation, with criticism only heightened in the wake of the Belgium attacks this week that left 31 dead and 300 wounded.