U.S. Secretary of State John Kerry said Wednesday that NATO members were prepared to intensify military operations against the Islamic State group, also known as ISIS. Kerry also praised British Prime Minister David Cameron for his efforts to seek approval from parliament for airstrikes against ISIS militants in Syria.

Kerry made the comments at NATO headquarters in the Belgian capital Brussels, where he urged foreign ministers of 27 other member countries to do more to fight the Sunni militant group’s strongholds in Iraq and Syria and throttle its international networks, the Associated Press (AP) reported. Kerry said he expected several other countries to plan how they might step up their efforts in additional military assistance and support aid such as medical facilities or refueling operations.

“We are going to defeat the efforts by these nihilistic, semi criminal -- not semi criminal, completely criminal, and abhorrent activities that are challenging civil life itself,” Kerry said, according to the Washington Post.

Kerry also commended Cameron's move to seek approval for British airstrikes against ISIS in Syria. The British parliament is expected to vote on the matter Wednesday. "This is a very important step. We applaud his leadership," Kerry said, according to the AP.

The 71-year-old also said that the Iraqi government was told in advance about America’s decision to send additional special forces to the country to intensify operations against the militant group by training Syrian rebel forces. His comments come soon after Iraqi Prime Minister Haider al-Abadi reportedly said late Tuesday that ground troops were not required as his country’s security forces were skilled enough to tackle ISIS.

Kerry said the U.S. had "full and total respect" for al-Abadi's leadership, and plans would go forward "in full consultation and with full consent of the Iraqi government," the AP reported.

On Tuesday, the U.S. Secretary of Defense Ashton Carter said that American forces will begin working with rebel forces in southern Syria. The new special operations forces “will help us garner valuable ground intelligence [and] further enhance our air campaign,” Carter said.

“The raids in Iraq will be done at the invitation of the Iraqi government and focused on defending its borders and building the [Iraqi Security Forces’] own capacity,” Carter said. “This force will also be in a position to conduct unilateral operations into Syria.”