A senior Republican senator appears to have issued a dire coronavirus warning to a group of business officials weeks before COVID-19 stormed onto US soil, but a senior aide contends the lawmaker has been raising such alarms about America's pandemic readiness for years.

A recording taken several weeks ago features the voice of a man who sounds like the Senate Intelligence Committee chairman telling members of the Tar Heel Circle and others about the then-coming virus during an exclusive luncheon event on Capitol Hill. That group is part of the North Carolina Society of Washington, DC, a private organisation that charges hefty dues to its members.

"There's one thing that I can tell you about this," the senator says in the recording. "It is much more aggressive in its transmission than anything that we have seen in recent history. It's probably more akin to the 1918 pandemic."

The North Carolina lawmaker was referring to the 1918-1919 influenza pandemic that infected about one-third of the world's population, killing 50 million worldwide and 675,000 in the United States, according to the Centers for Disease Control and Prevention (CDC).

Mr Burr, at a time when fellow Republican Donald Trump was saying publicly he expected the virus would "maybe go away," then offered some inside advice to the group of business sector representatives.

"Every company should be cognisant of the fact you may have to alter your travel," he said on the recording, first obtained by NPR. "You may have to look at your employees and judge whether that trip that they're making to Europe is essential or whether it can be done on video conference. Why risk it?"

But the source, who is close to Mr Burr, said Thursday that he has "been giving this message in public for years," adding "there is nothing said in that meeting that CDC and others weren't saying for weeks."

"His message has always been that we need to take this very seriously," added the source, granted anonymity to speak candidly.

The source noted the recording was made on 27 February, and pointed The Independent to a 3 February op-ed Mr Burr penned with GOP Senator Lamar Alexander for FoxNews.com in which they wrote: "Americans are rightfully concerned about the coronavirus" and the "ability of the virus to rapidly spread," calling that "alarming."

Caitlin Carroll, a spokeswoman for the chairman, said in a statement that "Senator Burr has been banging the drum about the importance of public health preparedness for more than 20 years."

"His message has always been, and continues to be, that we must be prepared to protect American lives in the event of a pandemic or bio-attack," she said. "Since early February, whether in constituent meetings or open hearings, he has worked to educate the public about the tools and resources our government has to confront the spread of coronavirus."

The same day the recording was made, Mr Trump – then still a coronavirus skeptic – talked about a "miracle" that would make the virus "disappear."

The president at that time did leave the door open that it "could get worse before it gets better."

More recently, however, Mr Trump has gotten much more serious about the virus and its spread, with The Johns Hopkins University putting the number of US cases at 9,415 with 68 deaths. (The school puts the total number of global cases at 222,642 with 9,115 deaths.)

Mr Trump now says it could trigger a US economic recession, with virus effects lingering into July or August.

On its website, the parent oganisation of the group to which Mr Burr spoke describes the Tar Heel Circle as "an organisation within the NCSW that sponsors non-partisan events bringing together influential North Carolinians with Society and Tar Heel Circle members to engage in dialogue regarding issues of the day in an informal and intimate setting. The mission of the Tar Heel Circle is to stimulate creative thinking to generate innovative solutions to the great questions and issues that face our state, nation and the world."