Updated

House Oversight Committee Chairman Darrell Issa issued a subpoena late Friday to Todd Park, President Obama's top adviser on technology, requiring him to appear before his committee next week and testify on the glitch-ridden rollout of ObamaCare.

The California Republican rejected the administration's offer to receive a briefing from Park later this month and said his unwillingness to testify "continues an unfortunate pattern of the current administration when it comes to matters of transparency and Congressional oversight."

“Reliable testimony about the status of efforts to address problems with HealthCare.gov is highly relevant to ongoing concerns about security vulnerabilities as well as legislative proposals Congress is currently considering that would allow Americans to keep individual insurance plans cancelled because of ObamaCare regulations,” Issa said in a letter to Park.

Issa claimed in an interview Thursday on Fox News that Park had engaged in a “pattern of interference and false statements” related to the testing of HealthCare.gov. and that White House spokesman Jay Carney "is paid to say things that just aren’t so."

Elijah Cummings, D-Md., the top Democrat on the committee, called on Issa to apologize to Park and Carney for making "unsubstantiated accusations against them," accusing his Republican counterpart of selectively releasing administration documents on the website's rollout.

Park said on Oct. 6 that the website was expected to draw around 60,000 simultaneous users but instead drew many more, around 250,000. The Obama administration has repeatedly insisted that the website’s repeated crashes were due to unexpectedly high traffic.

A White House spokesman criticized Issa's decision late Friday, but said the request is being reviewed and the administration plans to issue a response to the subpoena.

"This is an unfortunate and unnecessary step since we made clear several times that Todd Park is willing to testify," Rick Weiss, a spokesman for the Office of Science and Technology Policy, said in a statement. "We had hoped the Committee would work with us to find an alternative date to give Todd time to focus on the immediate task at hand: getting the website fixed."

Meanwhile, the White House has yet to formally take a position on a variety of proposals from Congress to address issues that have arisen since the insurance sign-ups launched on Oct. 1, including the ongoing backlash over health policy cancellations.

Sen. Mary Landrieu, D-La., has proposed requiring insurance companies to reinstate canceled plans, and Sen. Joe Manchin, D-W.Va., is supporting a measure to delay for a year the penalties for going without insurance.

Another Democrat, Sen. Jeanne Shaheen of New Hampshire, is asking Obama to extend the open enrollment period for insurance exchanges because of the widespread problems with the website.

The Associated Press contributed to this report.