The United States said it was prohibiting most non-US citizens from travelling to the country if they had been in Brazil in the last two weeks.

It comes two days after the South American nation became the country with the second highest number of coronavirus cases in the world. 

White House Press Secretary Kayleigh McEnany said the new restrictions would help ensure foreign nationals do not bring additional infections to the United States, but would not apply to the flow of commerce between the two countries.

National security adviser Robert O'Brien earlier said he hoped the move could be reconsidered at some point.

"We hope that'll be temporary, but because of the situation in Brazil, we're going to take every step necessary to protect the American people," Mr O'Brien said.

Brazil on Friday surpassed Russia to become the second worst hit country for coronavirus cases, second only to the United States, and now has over 347,000 people infected by the virus, the Health Ministry said.

Donald Trump said Brazil 'is having some trouble'

US President Donald Trump said on Tuesday he was considering imposing a ban on travel from Brazil.

"I don't want people coming over here and infecting our people. I don't want people over there sick either. We’re helping Brazil with ventilators. ... Brazil is having some trouble, no question about it," Mr Trump told reporters at the White House.

Mr O'Brien said the United States will look at restrictions for other countries in the Southern Hemisphere on a country-by-country basis.

Mr Trump suspended entry for most travellers from China, where the outbreak began, in January. In early March, he imposed travel restrictions on people coming from Europe.

The new restrictions bar most non-US citizens who have visited Brazil within the past 14 days. 

Green card holders, close relatives of US citizens and flight crew members, among select others, would be exempt.