WASHINGTON (REUTERS) - Officials ordered the US Capitol closed to much of the public starting on Thursday (March 12), one day after a staffer for a US senator from Washington state tested positive for the coronavirus.

Limited access to the Capitol would begin at 5pm ET (5am on Friday, Singapore time), the House and Senate Sergeant at Arms said in a statement.

The Capitol Visitor Centre will be closed and all public tours suspended, they said.

Lawmakers, staff, credentialed journalists and visitors with official business would still be allowed entry, Capitol officials said.

Congress had planned to take a week-long recess from Washington starting on Friday.

But it was unclear when the break would start as lawmakers negotiated with the Trump administration over legislation to provide economic relief as the number of US coronavirus cases continued to grow.

Democratic US Senator Maria Cantwell said on Wednesday she would shutter her Washington, DC office after one of her staffers tested positive for Covid-19.

Several Republican senators on Thursday also closed their Washington, DC offices as a precautionary measure.

"Other congressional employees are likely to test positive in the days ahead," Senator Tom Cotton said in a statement, adding he expected disruptions would be minimal given Congress'scheduled week-long recess that is set to start on Friday.

Mitt Romney also closed his Washington office.

Ted Cruz, who is among several Republican lawmakers who have self-quarantined after coming in contact with someone who later tested positive for the coronavirus, also closed his Washington office, his representatives said in a statement.

Local offices in the members' home districts remained open, the Republican senators said.