Secretary of State John Kerry called Nigerian President Goodluck Jonathan on Tuesday to offer U.S. support in the search for than 200 Nigerian schoolgirls kidnapped by militant group Boko Haram, the White House said.

Jay Carney, President Obama's top spokesman, said Kerry offered to send military personnel, law enforcement officials and hostage negotiators to Nigeria. However, Carney said the U.S. was not considering putting troops on the ground in Nigeria.

“We urge the Nigerian government to take action,” Carney said, calling the recovery of the kidnapping victims “Nigeria’s responsibility first and foremost.”

Though Carney said the Nigerian government welcomed the offer, he declined to get into further logistics of the discussion between Kerry and Jonathan.

Boko Haram abducted hundreds of Nigerian girls in recent weeks and threatened to sell the children into slavery.

The Obama administration previously said they were sharing intelligence with Nigerian officials, but Kerry’s phone call Tuesday represented the greatest offer of U.S. support to date in the ongoing crisis.

Carney said Obama and Kerry would discuss the Nigerian kidnappings at a White House meeting later Tuesday.