WASHINGTON (CNN) -- President Barack Obama told the nation in a televised address on Wednesday that the United States continues to face a threat even as the country targets terror groups.
"We can't erase every trace of evil from the world, and small groups of killers have the capacity to do great harm. That was the case before 9/11, and that remains true today," Obama said at the White House.
"That's why we must remain vigilant as threats emerge. At this moment, the greatest threats come from the Middle East and North Africa, where radical groups exploit grievances for their own gain. And one of those groups is ISIL -- which calls itself the Islamic State."
ISIS poses a threat to the Middle East, including the people of Iraq and Syria. "If left unchecked, these terrorists could pose a growing threat beyond that region, including the United States," Obama said.
Among the key points to address the threat from ISIS:
-- The United States will carry out a "systematic campaign of airstrikes" against ISIS. "...That means I will not hesitate to take action against ISIL in Syria, as well as Iraq. This is a core principle of my presidency: if you threaten America, you will find no safe haven," Obama said. ISIS is often called ISIL.
-- The United States will send an additional 475 service members to Iraq, Obama said. "As I have said before, these American forces will not have a combat mission," the President said. "We will not get dragged into another ground war in Iraq. But they are needed to support Iraqi and Kurdish forces with training, intelligence and equipment."
Also Wednesday, Obama shifted $25 million in military aid to Iraqi forces, including Kurdish fighters in the north combating the ISIS extremists. The aid could include ammunition, small arms and vehicles, as well as military education and training, State Department spokeswoman Marie Harf said.
Veteran diplomat: ISIS worse than al Qaeda
Former U.S. ambassador Ryan Crocker, who served in Syria, Iraq, Afghanistan, and Pakistan, told CNN on Wednesday that ISIS presents a bigger threat to America than al Qaeda.
"They are more numerous, they are better armed, they are far better financed, they are better experienced, and perhaps most critically there are several thousand of them who hold Western passports, including American passports," Crocker said. "They don't need to get a visa; they just need to get on a plane."
He added: "If we don't think we're on their target list, we are delusional."
Show of unity with Congress would help
After his meeting with top congressional leaders at the White House on Tuesday, Obama asked for their support to show the nation was united.
However, he insisted he already has the authority to ratchet up airstrikes against ISIS under war power granted more than a decade ago to fight al Qaeda. ISIS formed from some al Qaeda affiliates but is separate from the central leadership of the terrorist organization behind the September 11, 2001 attacks on the United States.
On Wednesday, two senior legislators -- one from each party -- told CNN's Dana Bash that a congressional vote on military action against the jihadists was unlikely despite calls for one by many of their colleagues.
While some in Congress want to vote on the matter, taking up such a volatile issue as military action weeks before the November elections may be politically dangerous.