The Obama administration will prepare a campaign to destroy the Islamic State militant group that may last for several years, reports the New York Times.  

Citing U.S. official's latest report, the Times reveals that the White House plan involves three phases that some Pentagon officials believe will last for at least three years.

The first phase, airstrikes against ISIS, is currently underway in Iraq. Since August 8, the U.S. has launched 143 attacks against ISIS targets. The second phase involves an intensified effort to train, advise, and equip the Iraqi Army, Kurdish Peshmerga fighters, and any Sunni tribesmen willing to fight their ISIS co-religionists. This second phase will likely begin after Iraq forms a new government.

The third phase would require airstrikes against ISIS inside Syria. The Times warns that this may be the most risky phase, as government of Bashar Assad in Damascus recently told Obama administration to refrain from launching airstrikes against ISIS in Syria until given permission to do so.

According to Fox News, Obama was scheduled to outline his plan in a meeting Tuesday with House and Senate leaders before addressing the nation in a speech Wednesday, the eve of the 13th anniversary of the September 11, 2001, terror attacks. However, a senior Obama administration official told Fox News that immediate action against the Middle East will likely not be announced in the address. Instead, Obama will likely update the United States on what the strategy is to deal with the militant group, saying the administration wants "people to understand how he's approaching this."

ISIS recently beheaded two American journalists, Steven Sotloff and James Foley, in an attempt to spread terror and deter future airstrike attacks from the U.S.

ISIS has blamed Obama for refusing to heed ISIS's warnings and end military strikes, and have also threatened the life of a British captive, David Cawthorne Haines.

On Sunday, President Obama assured the United States that the government will stop at nothing to defeat ISIS and ensure justice.  

"What I want people to understand," Obama told NBC's "Meet the Press," "is that over the course of months, we are going to be able to not just blunt the momentum" of the militants. "We are going to systematically degrade their capabilities; we're going to shrink the territory that they control; and, ultimately, we're going to defeat them," he added.