WASHINGTON (JTA) — Citing possible threats to the homeland among other considerations, President Obama pledged to “destroy”  ISIS, using airstrikes and training the Iraqi army to combat the terror organization.

“Our objective is clear,” Obama said, speaking from the White House Wednesday evening on the eve of the 13th anniversary of the Sept. 11 2001 terrorist attacks. “We will degrade and ultimately destroy ISIL through a comprehensive and sustained counter-terrorism strategy.”

ISIL is the acronym for the Islamic State of Iraq and the Levant, another name for the group.

The president noted the possible threat to American targets, including from westerners who have joined the terrorist group’s fight and who may return home undetected.

“While we have not yet detected specific plotting against our homeland, ISIL leaders have threatened America and our allies,” he said.

“Our intelligence community believes that thousands of foreigners  — including Europeans and some Americans — have joined them in Syria and Iraq,” Obama said. “Trained and battle-hardened, these fighters could try to return to their home countries and carry out deadly attacks.”

A White House fact sheet posted at the time of the speech said that “over 100 foreign fighters from the United States have traveled or attempted to travel to the conflict.”

Obama said there may also be strikes on ISIS in Syria, but this would not translate into any cooperation with the Bashar Assad regime, which the Obama administration said she remove itself from power after three years of a bloody civil war.

“In the fight against ISIL, we cannot rely on an Assad regime that terrorizes its own people; a regime that will never regain the legitimacy it has lost,” he said. “Instead, we must strengthen the opposition as the best counterweight to extremists like ISIL, while pursuing the political solution necessary to solve Syria’s crisis once and for all.”

Obama did not say whether the United States would cooperate with Iran, which is also assisting Iraq and Syria in the bid to stop ISIS.