MANAMA, Bahrain -- U.S. Defense Secretary Ash Carter said Saturday that as many as 200 more American troops are being sent to Syria to help Kurdish and Arab fighters capture the Islamic State of Iraq and Syria’s key stronghold of Raqqa.

The extra troops will include special operations forces and are in addition to 300 U.S. troops already authorized for the effort to recruit, organize, train and advise local Syrian forces to combat ISIS.

Addressing a security conference in Bahrain, Carter said the aim is to create, along with America’s Middle East allies, a tornado of pressure on ISIS’ Raqqa headquarters, CBS Radio News’ Larry Miller reports.

“The United States has interests here that it cannot walk away from,” Carter said.

Carter also took gentle jabs at U.S. Middle East partners for failing to provide more military muscle in the broader campaign to defeat ISIS and counter extremism.

Without mentioning any by name, Carter suggested the U.S. has been the target of disingenuous criticism from “regional powers here in the Middle East” for not doing more to help fight extremism.

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“I would ask you to imagine what U.S. military and defense leaders think when they have to listen to complaints sometimes that we should do more, when it’s plain to see that all too often, the ones complaining aren’t doing enough themselves,” he said.

He said it is not unreasonable for Washington to expect regional powers who oppose extremism in the Middle East to do more to help fight it, “particularly in the political and economic aspects of the campaign.”

Carter noted that many Sunni-led Gulf countries have expressed concern about the spread of Iranian influence in the region.

“The fact is, if countries in the region are worried about Iran’s destabilizing activities - a concern the United States shares - they need to get in the game. That means getting serious about starting to partner more with each other, and investing in the right capabilities for the threat.”

Carter said the 200 extra troops going to Syria will help local forces in their anticipated push to retake Raqqa, the de facto capital of the extremist group’s self-styled caliphate, and to deny sanctuary to ISIS after Raqqa is captured.

He said President Obama approved the troop additions last week.

“These uniquely skilled operators will join the 300 U.S. special operations forces already in Syria, to continue organizing, training, equipping, and otherwise enabling capable, motivated, local forces to take the fight to ISIL,” Carter said in his address to the IISS Manama Dialogues in the Bahraini capital, using an alternative acronym for ISIS.

“By combining our capabilities with those of our local partners, we’ve been squeezing ISIL by applying simultaneous pressure from all sides and across domains, through a series of deliberate actions to continue to build momentum,” he said.

The military push is complicated by the predominant role played by local Kurdish fighters, who are the most effective U.S. partner against ISIS in Syria but are viewed by Turkey -- a key U.S. ally -- as a terrorist threat.

A senior defense official told The Associated Press the troop boost announced by Carter will give the U.S. extra capability to train Arab volunteers who are joining the Raqqa push but are not well trained or equipped. The official spoke on condition of anonymity to discuss details of internal Pentagon planning.