Republican lawmaker Rand Paul of Kentucky has become the first US senator to test positive for the novel coronavirus, which has infected more than 33,000 people across the country.

In a statement Sunday on Twitter, Paul's office said he is feeling fine and is in quarantine.

"He is asymptomatic and was tested out of an abundance of caution due to his extensive travel and events. He was not aware of any direct contact with any infected person," it said.

The announcement came amid a struggle between Democrats and Republicans to reach an agreement on emergency coronavirus legislation.

Two weeks ago, Paul attended a black-tie social event in Louisville, Kentucky and several people who attended the same event later tested positive, according to CNN.

Shortly after the news of the confirmed result, Utah Republican Senators Mike Lee and Mitt Romney said they would self-quarantine for two weeks.

President Donald Trump said he spoke with Paul and the senator was feeling good.

"My friend (always there when I’ve needed him!), Senator @RandPaul, was just tested “positive” from the Chinese Virus. That is not good! He is strong and will get better. Just spoke to him and he was in good spirits," Trump wrote on Twitter.

On Wednesday, Rep. Mario Diaz-Balart, a Florida Republican, and Democratic Rep. Ben McAdams of Utah announced they had tested positive for the virus.

Paul "expects to be back in the Senate after his quarantine period ends and will continue to work for the people of Kentucky at this difficult time," said his office.

According to Johns Hopkins University, the coronavirus, officially known as COVID-19, has infected nearly 336,000 worldwide, including more than 33,270 in the US, and killed over 14,600, including 417 in the US.

The virus emerged in the Chinese city of Wuhan in December.