Egyptian Airstrikes in Libya Were Not Coordinated With US: Sources

— -- The retaliatory airstrikes conducted by Egypt inside Libya early Monday were not considered to be a part of the US-led coalition effort to counter ISIS, senior U.S. defense officials tell ABC News.

The strikes come after ISIS posted a new online video purporting to show the execution of 21 Egyptian Christians.

Although Egypt is considered a member of the coalition, officials say these strikes in Libya were not in any way coordinated with coalition leadership and Operation Inherent Resolve.

"This was not a coalition strike," a senior defense official told ABC News. "This was a decision made by the Egyptian government and I have seen no indication the U.S. was involved in any way."

The U.S. is operating under strict guidelines set forth by President Obama last year that authorizes strikes against ISIS only within the boundaries of Iraq and Syria, meaning that these airstrikes targeting ISIS in Libya are the first of their kind.

Senior officials say they were also unaware of any prior warning the Egyptians may have given to the U.S. before striking ISIS targets in Libya.

According to the latest press release from the Pentagon, Egypt has yet to officially contribute to coalition airstrikes in Iraq or Syria. Countries who have include: U.S., Australia, Belgium, Canada, Denmark, France, Netherlands, the United Kingdom, Bahrain, Jordan, Saudi Arabia and the United Arab Emirates.

U.S. officials have been unable to provide any assessment of how effective the Egyptian strikes in Libya may have been.

Senior military commanders have warned in recent months of signs that ISIS attempting to gain influence inside Libya, but at this point there is no plan to begin hitting targets there. As one official put it, " We don’t think there is very much there."

Yet other counterterrorism officials in Washington caution that although ISIS may not have a unified network of militants inside Libya, they do have a significant number of supporters and sympathizers in Libya, that along with other violent extremists there, pose a serious security threat inside the country.