WILMINGTON, Del. — President-elect Joe Biden met Thursday with governors from both parties and criticized President Donald Trump’s unprecedented attempt to block the peaceful transition of power, saying it was hindering the flow of information about programs to develop a vitally important coronavirus vaccine.

“Unfortunately, my administration hasn’t been able to get everything we need,” Biden said during a video conference with the National Governors Association’s leadership team, which consists of five Republicans and four Democrats.

His remarks highlighted the stakes of the Trump administration’s refusal to begin a formal transfer of power to Biden’s team. Besides being a pillar of American democracy, it is especially important this year since Biden will be inheriting responsibility for managing the worst public health crisis in a century. The president-elect also has been denied access to other critical information, including security briefings.

Participating from a theater in Wilmington, Delaware, with Vice President-elect Kamala Harris, Biden specifically cited Operation Warp Speed, the federal government’s partnership with private pharmaceutical companies to develop a COVID-19 vaccine.