American drones are now part of the search.
Lawmakers said U.S. efforts are coming far too late.
CBS News' Nancy Cordes reports there's a big debate on Capitol Hill over how much the U.S. can do and should do in Nigeria. The State Department has now sent five officials to advise the Nigerian government.
State Department spokeswoman Jen Psaki said, "As you know, of course, this is a difficult mission and we're looking for the girls in an area roughly the size of New England."
The U.S. government may be increasing its role in the search, but Secretary of State John Kerry insists that role is a supporting one.
"The president has all options with respect to the future," Kerry said. "We're dealing with the government of another country. That's always got its diplomatic requirements."
But some on Capitol Hill think the administration should be doing more.
Sen. Susan Collins, R-Maine, believes a delay in providing aid may have catastrophic repercussions.
"There's a feeling among my colleagues that we simply were too slow," said Collins. "... Some of them may have already been shipped across the border, sold into slavery, forced into early marriages ... I cannot believe that this much time has elapsed without us taking these basic steps to help."
In an interview with The Daily Beast, Sen. John McCain, R-Ariz., took a swipe at the government's position, saying he "wouldn't be waiting for some kind of permission from some guy named Goodluck Jonathan."
Complicating matters, the U.S. government opposes Nigeria's latest stance on working to free the girls by negotiating with Boko Haram.
White House press secretary Jay Carney said, "It is the policy of the United States to deny kidnappers the benefits of their criminal acts, and that includes ransoms or concessions."
Some lawmakers believe the U.S. should have sent in special forces weeks ago to try to rescue the girls, but the White House has always insisted that it's not contemplating sending in boots on the ground right now - that if there are going to be military officials in the country it's going to be in a supporting role only.