While House Republicans and Trump appear to be aligned in their desire to investigate Biden’s fitness to serve, there is some frustration brewing among congressional committees about how quickly the Trump administration is responding to some of their requests, according to multiple GOP congressional sources familiar with the matter.

WASHINGTON—The Republican-led House Oversight Committee on Thursday requested interviews with former President Joe Biden’s physician and several top aides as it reopened a probe into what was known about Biden’s health and age-related decline while in office.

Sen. Ron Johnson is launching an investigation into former President Biden's health, he told Axios. Why it matters: The news of Biden's cancer diagnosis as well as new revelations about the White House's efforts to hide the former president's deteriorating health has reignited attacks from the GOP about Biden's fitness to carry out the duties of commander in chief.