Saudi Arabia's statement that it is "ready" to participate in ground operations inside Syria against the Islamic State is a direct response to Defense Secretary Ash Carter's blunt assessment that the Gulf States are not pulling their weight in the international coalition formed to defeat the radical Sunni group, according to a White House spokesman.

"Secretary Carter made a request of a number of his counterparts who are part of our counter-ISIL coalition, including the Saudis, asking them to consider ways they could enhance … and even increase, their contributions to our counter-ISIL efforts," White House spokesman Josh Earnest said Friday. All "those requests have included additional military support."

A Saudi general told a state-run TV station on Thursday "the kingdom is ready to participate in any ground operations that the coalition may agree to carry out in Syria." Reportedly, the biggest Sunni-Arab nation is mulling deploying thousands of special forces troops.

Many observers expect a more definitive announcement to come during next week's NATO summit in Brussels.

"This is one of the great ironies, which is that the countries of the region have made the least contributions to the counter-ISIL coalition, including the Gulf countries," Carter told CNN Jan. 24, using the Obama administration's preferred acronym for the Sunni terrorist group. "The Gulf States can make contributions to galvanizing recruiting such local forces, he added. "Up to now, they haven't done enough; we want them to do more."

Earnest said Carter will reiterate his request to his Saudi, and other coalition-member, counterparts during a meeting on the edges of the NATO summit.

"They have a pretty advanced military in Saudi Arabia and they have special operations forces that do have unique capabilities that could advance the goals of our counter-ISIL campaign," Earnest said. "But in terms of the specifics about what they're prepared to commit to this effort … I don't want to speak for them."

Earnest said he hopes the Saudi commitment will spur additional contributions from other countries, but he stressed that Carter will tell his counterparts that they need to do more, and they must do so in coordination with each other.

"And so, that does mean that the Saudis can't just next week, send in troops into Syria," Earnest said. "We want to make sure that their commitment is integrated into the overall effort and integrated with the contributions that are made by other countries."