The U.S. Senate voted Thursday to start debate on a 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.

But 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.