Washington, Mar 11 (IANS): A convoy of truckers circled the Capital Beltway, a key interstate highway that surrounds Washington, D.C., for a fourth consecutive day since their demonstration against Covid-19 restrictions began earlier this week.

On Thursday, Senator Ted Cruz visited the convoy camping outside a speedway in Hagerstown, a Maryland city approximately 110 km northwest of the capital, before riding in one of the trucks, reports Xinhua news agency.

The Texas Republican also held a press conference in Washington, D.C., alongside Brian Brase, an organiser of the so-called "People's Convoy", after the ride.

Cruz's appearance came a day after he and Senator Ron Johnson, a Republican from Wisconsin, met the convoy participants on Capitol Hill.

The convoy, a spinoff from protests in Canada staged by truckers upset with vaccine requirements earlier this year, is calling for an end to the national emergency concerning the Covid-19 pandemic in the US that led to what they called "overreaching mandates".

The Transportation Security Administration (TSA) announced on Thursday that it will "extend the security directive for mask use on public transportation and transportation hubs for one month, through April 18", as states and cities were easing Covid-19 restrictions.

The TSA said in a statement that the Centers for Disease Control and Prevention (CDC) "will work with government agencies to help inform a revised policy framework for when, and under what circumstances, masks should be required in the public transportation corridor".

"This revised framework will be based on the Covid-19 community levels, risk of new variants, national data, and the latest science. We will communicate any updates publicly if and/or when they change," it added.

The truckers started hitting the Capital Beltway on Sunday and took a break on Wednesday due to rain.

Capitol Police said previously they did not expect the convoy to cause security problems in the Washington metropolitan area.