Obama set to endorse Joe Biden for president

• The 77-year-old former vice president is the Democratic Party's presumptive nominee.

Obama, a popular two-term president and Donald Trump's predecessor in the White House, will release a video Tuesday with his endorsement of Biden, the sources said.

The 77-year-old former vice president is the Democratic Party's presumptive nominee, after his lone remaining rival Bernie Sanders dropped out of the race last week and endorsed Biden on Monday.