WILMINGTON, Del. (NewsNation Now) — President-elect Joe Biden and vice president-elect Kamala Harris will receive a national security briefing on Tuesday, according to the official schedule.

A source close to the transition team told NewsNation that the briefing will be conducted by former U.S. government officials because “ascertainment” has not been obtained by the General Services Administration.

Earlier on Monday, Biden warned of “dire consequences” if President Donald Trump and his administration refused to coordinate with his transition team on the coronavirus pandemic and block briefings on national security, policy issues and vaccine plans.

“More people may die if we don’t coordinate,” Biden told reporters during a news conference in Wilmington, Delaware.

This is a developing story.