Washington, Feb 10 : White House Press Secretary Jen Psaki said that the US government is watching the protests staged by truckers in Canada "very closely". Speaking to reporters during a daily briefing, Psaki expressed concern over a trucker blockade at the Ambassador Bridge, Canada's busiest link to the US accounting for roughly a quarter of trade between the two countries, reports Xinhua news agency. "The blockade poses a risk to supply chains for the auto industry because the bridge is a key conduit for motor vehicles, components, and parts; and delays risk disrupting auto production," she said, adding that they are also "tracking potential disruptions to US agricultural exports from Michigan into Canada". The ongoing protests in Ottawa have paralysed parts of the Canadian capital over the past two weeks, as truckers honked in anger over Covid-19 vaccine mandates. Ottawa Mayor Jim Watson declared a state of emergency on Sunday, saying the situation was "completely out of control". The US Department of Homeland Security has reportedly warned law enforcement across the country that similar protests could soon begin here. A bulletin issued on Tuesday by the Department to state and local officials said that the agency "has received reports of truck drivers planning to potentially block roads in major metropolitan cities in the US in protest of, among other things, vaccine mandates for truck drivers". "While there are currently no indications of planned violence, if hundreds of trucks converge in a major metropolitan city, the potential exists to severely disrupt transportation, federal government operations, commercial facilities, and emergency services through gridlock and potential counter-protests." /IANS