The leader of the Islamic State militant group is expected to declare “jihad against America” following U.S. airstrikes on Islamist targets in Iraq, a Middle East watcher said.

Jihadi websites lit up Friday saying that Abu Bakr al-Baghdadi will be calling on supporters throughout the world to attack the U.S. homeland, said Steve Stalinsky, the executive director of the Middle East Media Research Institute, a nonprofit group that tracks media networks in the Middle East.

The Islamic State — which renamed itself from the Islamic State of Iraq and Syria — is a breakaway Al Qaeda group that has long called for the destruction of the U.S. Two days ago, a video from the group said it would raise its “flag on the White House,” according to a CNN translation.

KHAZAIR, IRAQ - JULY 03: A Iraqi family who fled recent fighting near the city of Mosul prepares to sleep on the ground as they try to enter a temporary displacement camp but are blocked by Kurdish soldiers on July 3, 2014 in Khazair, Iraq. The families, many with small and sick children, have no shelter and little water and food. The displacement camp Khazair is now home to an estimated 1,500 internally displaced persons (IDP's) with the number rising daily. Tens of thousands of people have fled Iraq's second largest city of Mosul after it was overrun by ISIS (Islamic State of Iraq and Syria) militants. Many have been temporarily housed at various IDP camps around the region including the area close to Erbil, as they hope to enter the safety of the nearby Kurdish region. Spencer Platt/Getty Images

An Iraqi family that fled fighting near the city of Mosul. (Spencer Platt/Getty Images)

According to MEMRI, Twitter users associated with the Islamic State responded to the U.S. strikes on Friday with tweets including, “Today Mosul and tomorrow Seattle.”

"#Obama_announces_bombing_Islamic_State and the mujahideen respond: today Mosul and tomorrow Seattle. Say Allah Akbar oh Muslims, the bells of war have been sounded" (Image source and translation via MEMRI)

“#Obama_announces_bombing_Islamic_State and the mujahideen respond: today Mosul and tomorrow Seattle. Say Allah Akbar oh Muslims, the bells of war have been sounded” (Image source and translation via MEMRI)

"I call on Muslims to target all American interests and American citizens, all of them without exception." (Image source and translation via MEMRI)

“I call on Muslims to target all American interests and American citizens, all of them without exception.” (Image source and translation via MEMRI)

Pentagon officials wouldn’t say whether Friday’s airstrike were marking the beginning of a lengthier campaign against the group. TheBlaze reported last week that the Obama administration called defending Christian and other minority groups under attack from the Islamic State a top priority.

The Islamic State has been seizing cities across northern Iraq with the aim of establishing a caliphate across the Middle East. More than 200,000 Christians and other minorities have fled their homes out of fear after being warned they would be killed if they did not convert to Islam.

“Airstrikes might not be enough to stop this group,” a U.S. official who has traveled in the region said. “The West may need a much broader campaign to destroy this radical group and stop them before they get any bigger.”

James Carafano, a senior defense analyst with the conservative Heritage Foundation think tank, called the Islamic State’s latest offensive actions  in Iraq and Syria “truly worrying.”

“They are looking for weak spots to go on the offensive and they are picking targets of strategic significance,” Carafano said. “[These] initiatives suggest [the Islamic State] is looking at both the Syria and Iraq front for new opportunities … that’s dangerous.”

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