Photo taken on Feb. 9, 2021 shows the U.S. Capitol building in Washington, D.C., the United States. (Xinhua/Liu Jie)

Senate Republicans, who oppose the high price tag of the relief package, could use certain tools to delay a final vote on the bill by hours or even days.

WASHINGTON, March 4  -- U.S. Senate voted to start debate on the 1.9-trillion-dollar COVID-19 relief package amid Republican opposition, as Democrats hope to send the bill to President Joe Biden's desk before unemployment benefits expire in mid-March.

The upper chamber approved a procedural step in a 50-50 vote along party line, with Vice President Kamala Harris breaking a tie.

Senate Republicans, who oppose the high price tag of the relief package, could use certain tools to delay a final vote on the bill by hours or even days.

"I just objected to skipping past the reading of the Democrats' 628-page bill that was just introduced minutes ago," Republican Senator Ron Johnson said on Twitter Thursday afternoon.

"If they're going to add nearly $2T to the national debt at least we should know what's in the bill," Johnson said.

Senate Democratic Leader Chuck Schumer, meanwhile, said on Twitter that "it's great GOP Senator Ron Johnson wants to read the American Rescue Plan on the Senate floor, it gives Americans another opportunity to hear what's in it!"

"Direct checks, vaccine funding, resources for schools, rental assistance, small biz (business) help, anti-poverty measures, and more," Schumer said, noting that "We will pass the bold COVID response Americans urgently need."