Former U.S. Vice President Joe Biden has officially clinched the Democratic presidential nomination after securing 1,991 delegates, setting him up to challenge incumbent Donald Trump in the 2020 presidential election.

Biden swept all seven states holding presidential primaries on Tuesday – Maryland, Indiana, Rhode Island, New Mexico, Montana, South Dakota and Pennsylvania – plus the District of Columbia. 

He had been inching closer to the delegate number all week as votes continued to be tallied.

In a statement released soon after the needed number was reached, Biden said the country needs leadership.  

"This is a difficult time in America's history. And Donald Trump's angry, divisive politics is no answer. The country is crying out for leadership. Leadership that can unite us," a portion of the statement reads. 

Biden spent 36 years in the Senate before becoming Barack Obama's vice president. This is the 77-year-old's third bid for the presidency and his success in capturing the Democratic nomination was driven by strong support from black voters.

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The Democratic National Committee will hold their convention in mid-August, where Biden will officially be nominated to represent their party in the general election.

The country faces the worst rate of unemployment since the Great Depression. And civil unrest has erupted in dozens of cities following the death of George Floyd, a black man who died when a white Minneapolis police officer pressed his knee onto his neck for several minutes even after he plead for air and stopped moving.