US President-elect Joe Biden held a press conference on Thursday after speaking virtually with governors on the fight against the coronavirus.
In his remarks, Biden criticized President Donald Trump for failing to cooperate with the transfer of power.
Biden warned that the US could reach 400,000 coronavirus deaths by early February "if nothing fundamentally changes" in the pandemic response.
"There is no excuse not to share the data and let us begin to plan," he added.
On Trump's refusal to concede the election, Biden said, "I don't know his motive, but I just think it's totally irresponsible...It sends a horrible message about who we are as a country."
"What the president is doing now is really going to be another incident where he will go down in history as being one of the most irresponsible presidents in American history," he charged.
Biden added he has not ruled out legal action over Trump’s blocking of the transition, but said he believes it would take a long time and not substantially speed things up.
"I'm making a judgment based on many years of experience in how to get things done with the opposition," said Biden.