FILE: U.S. Department of Health & Human Services (HHS) Secretary Kathleen Sebelius testifies before a House Education and the Workforce Committee hearing on Capitol Hill in Washington, June 4, 2013. (REUTERS/Jim Bourg)

Health and Human Services Kathleen Sebelius is negotiating with House Republicans over when she will appear before the House Energy and Commerce Committee to answer questions about the troubled rollout of enrollment for the new federal health-insurance exchange, according to agency spokeswoman Joanne Peters, but has not agreed to appear at a hearing scheduled on Thursday.

“We are in close communication with the committee and have expressed our desire to be responsive to their request," Peters said in a statement. "We fully intend for the Secretary and other HHS officials to testify before Congress as early as next week, as they have numerous times in the past, but nothing is confirmed at this time."

Sebelius is scheduled to be in Phoenix, Ariz. on Thursday, according to an administration official who asked not to be identified because the talks are ongoing.

House Speaker John Boehner's (R-Ohio) spokesman Brendan Buck sent out an e-mail Monday saying this still amounted to a refusal to appear. "Despite its window dressing, this is a statement that Sebelius will NOT testify on Thursday," Buck wrote.

Boehner called upon Sebelius Monday to testify, saying in a statement, "Secretary Sebelius must change her mind and appear at this week’s hearing in the House. With more than one trillion taxpayers being spend on a completely defective program, Congress is going to get to the bottom of this debacle.”

Peters said agency officials "have always indicated to the committee that she intended to testify but that she had a scheduling conflict. We continue to work with them to find a mutually agreeable date in the near future.”

In an interview on MSNBC Monday, White House communications director Jennifer Palmieri said that while Sebelius could not make the hearing, “They’ll work this out so there’s a representative there” from HHS.