In a statement after the speech, the Acting Secretary of Homeland Security Chad F. Wolf said the restrictions do not apply to US citizens, legal permanent residents and their immediate families. He said he planned to issue an order within the next 48 hours directing such individuals currently in the European Union’s border-free Schengen area to only return home via “select airports” with enhanced screening measures.

Trump also announced economic measures including the provision of US$50 billion in low-interest loans for small businesses disrupted by the spread of Covid-19, the disease caused by the coronavirus, and tax deferrals.

“Using emergency authority, I will be instructing the Treasury Department to defer tax payments, without interest or penalties for certain individuals and businesses are negatively impacted,” Trump said. “This action will provide more than US$200 billion of additional liquidity to the economy.”

The 10-minute speech was only Trump’s second address from the Oval Office – a solemn format sparingly used by previous presidents to deliver messages about national emergencies or major policy initiatives.

In January 2019, Trump delivered a similar prime-time address in the midst of a partial government shutdown. He used that speech to ask Congress to give him US$5.7 billion to build a border wall with Mexico.

Also after the speech, the White House said Trump cancelled a three-day trip to Colorado and Nevada that was set to begin on Thursday. A Thursday reception at the White House to celebrate St. Patrick’s Day and the visit of the Irish Prime Minister Leo Varadkar was also called off.

US coronavirus cases could hit ‘many millions’, top health official tells Congress

The total number of Covid-19 infections in the US surpassed 1,000 by Wednesday, according to a provisional count by major news outlets, with 31 deaths reported. The official nationwide count by the Centres for Disease Control and Prevention (CDC) is lower, since it is updated at noon, based on figures submitted by individual states by 4pm the day earlier.

The latest figures are markedly higher from the CDC’s count of around 423 infections and 19 deaths at the start of the week.

Almost three-quarters of American states, as well as the District of Columbia, have reported infections.

Dr Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said in a congressional hearing that “many millions” in the US could be infected if appropriate measures are not taken immediately.

“How much worse we'll get will depend on our ability to do two things: to contain the influx of people who are infected coming from the outside, and the ability to contain and mitigate within our own country,” he said.

In the same house oversight committee hearing, comments by the director of the CDC, Robert Redfield, showed how seriously the US viewed the situation in Europe.

“A real threat right now is Europe. That's where the new cases are coming in. Europe is the new China,” Redfield told lawmakers.

The congressional hearing devolved into a partisan fray as Democrats castigated the administration for its haphazard response to the crisis.

Coronavirus along with plunging stocks pose threat unlike any Trump has faced

In a Twitter post seen as a response to those attacks, Trump tweeted, just hours before his address: “Someone needs to tell the Democrats in Congress that CoronaVirus doesn’t care what party you are in. We need to protect ALL Americans!”

Many Democrats and some lawmakers in his own party have pushed back against Trump’s proposal for a payroll tax holiday to cushion the economic blow caused by the coronavirus outbreak.

Trump reiterated his call for the measure in Wednesday evening’s address.

“I am calling on Congress to provide Americans with immediate payroll tax relief, hopefully they will consider this very strongly,” he said. “We are at a critical time in the fight against the virus.”