WASHINGTON (AP) — President Barack Obama told congressional leaders Tuesday he has the authority he needs to launch a broader military campaign to root out violent extremists in Iraq and Syria, a day before outlining his plans to the American people in a prime-time address.

The White House said the president told lawmakers he still would welcome action from Congress that "would aid the overall effort and demonstrate to the world that the United States is united in defeating the threat from ISIL." That could take the form of specific authorization to fund counterterrorism efforts, as well as to train and equip more moderate elements of the opposition to the Bashar Assad government in Syria.

The president's broader strategy to confront the Islamic State militants may also include more wide-ranging airstrikes against targets in Iraq and possibly in Syria. Obama has also sought military and political commitments from Europe, the Middle East and elsewhere.

"The president believes this is a high national security priority," White House spokesman Josh Earnest said.

For Obama, a sustained U.S. intervention in the Middle East is at odds with the vision he had for the region when he ran for president on a pledge to end the war in Iraq, where the role of American fighting forces drew to a close nearly three years ago. The timing of his announcement Wednesday night was all the more striking, with Obama's address to the nation scheduled just hours before anniversary commemorations of the Sept. 11, 2001, attacks that drew the U.S. into war in Afghanistan and Iraq.

Even before Obama's meeting with Senate and House leaders, some lawmakers had suggested a congressional vote on the president's plans was unlikely before the midterm elections in November.

"As a practical matter, I don't really see the time that it would take to really get this out and have a full debate and discuss all the issues," said Rep. Howard "Buck" McKeon, R-Calif., chairman of the House Armed Services Committee.

However, Senate Minority Leader Mitch McConnell, R-Ky., said Obama should seek congressional approval for whatever he has decided to do.

"I think it is to his advantage and the country's advantage to have Congress buy into that," McConnell said before joining other Republican and Democratic leaders in the Oval Office Tuesday afternoon for a meeting with Obama that lasted just over an hour.

None of the leaders spoke to reporters as they left the White House.

However, an aide to House Speaker John Boehner said the Ohio Republican expressed support for efforts to increase the effectiveness of the Iraqi security forces and for equipping the Syrian opposition. Boehner also said he would support the deployment of U.S. military personnel to Iraq in a training and advisory role and to "assist with lethal targeting" of Islamic State leadership, according to the aide, who spoke only on condition of anonymity in order to discuss the private meeting.

Beyond authorizing military force, Congress could show its support for a broader mission by authorizing two initiatives Obama outlined earlier this year: $5 billion to fund counterterrorism missions and $500 million for arming and training Western-backed Syrian rebels.

The U.S. is already launching airstrikes against Islamic State targets inside Iraq, a mission undertaken at the invitation of the Iraqi government and without formal authorization from Congress. But the scope of the mission has been relatively limited to strikes that help protect American interests in the region and prevent humanitarian crises.

U.S. officials say Obama is expected to loosen those limitations and open a broader counterterrorism campaign against the militants in Iraq. And following the group's shocking beheading of two American journalists in Syria, Obama began more seriously considering extending strikes into Syria.

People who have spoken with Obama in recent days said it appeared likely he would take that step. At a private dinner Monday night with foreign policy experts, Obama emphasized the importance of viewing the Islamic State as one organization, not two groups separated by a border.

Obama's spokesman has said the president is willing "to go wherever is necessary to strike those who are threatening Americans." However, Obama has continued to rule out sending U.S. troops into ground combat operations in the Middle East.

In a shift for a war-weary nation, new polls suggest the American people would support a sustained air campaign. A Washington Post-ABC News poll released Monday showed 71 percent of Americans support airstrikes in Iraq, up from 54 percent just three weeks ago. And 65 percent say they support extending airstrikes into Syria.

Taking that latter step would raise legal and geopolitical issues that Obama has long sought to avoid, particularly without formal congressional authorization.

Unlike in Iraq, Obama would not be acting at the invitation of a host government. However, some international law experts say airstrikes could be justified as a matter of self-defense if Obama argues the Islamic State poses a threat to the U.S. and its allies from inside Syria, whose government is unwilling or unable to stop it.

Another possibility: Although the U.S. has said it will not coordinate with Syrian President Assad, his government could give back-channel consent to American strikes. The U.S. has a similar arrangement with the Pakistani military for U.S. drone strikes there, even though Pakistani officials publicly condemn the American actions.

Obama would still have to contend with the notion that American strikes against the Islamic State were actually helping Assad, who has overseen Syria's bloody civil war. The U.S. has long called for Assad to leave power, and the Islamic State is one of the groups inside Syria that is seeking to oust him.

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Associated Press reporters Donna Cassata, Bradley Klapper, David Espo, Alan Fram, and Robert Burns contributed to this report.

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