The US House of Representatives overwhelmingly passed an $8.3 billion funding bill Wednesday to respond to the growing coronavirus threat as California declared a state of emergency after reporting the first US death outside of Washington state, which itself announced that a 10th person had died from the coronavirus.

"The State of California is deploying every level of government to help identify cases and slow the spread of this coronavirus," Governor Gavin Newsom said in a statement. "This emergency proclamation will help the state further prepare our communities and our health care system in the event it spreads more broadly."

California health officials said the first person to die from the virus in the state was an elderly patient in Placer County, near Sacramento.

The patient, who had underlying health conditions, had been in isolation at a hospital. Officials believe the patient was likely exposed to the virus last month on a cruise ship, which departed from San Francisco to Mexico.

The number of confirmed cases in California rose to 51 on Wednesday, the most of any state, as health officials in Los Angeles County announced six new cases and declared a state of emergency.

Three of the patients among the newly confirmed cases had recently traveled to northern Italy, one of the regions hardest hit by the outbreak. The remaining three new cases were either family members of the travelers or worked in close contact with them.

"This is not a response rooted in panic," said Kathryn Barger, chair of the Los Angeles County Board of Supervisors, in a news conference Wednesday. "We've been preparing with our local, state and federal partners for the likelihood of this scenario."

Washington state now has at least 39 confirmed infections, according to its health department. The Seattle area was trying to contain a worsening crisis that has seen the virus overrun a suburban nursing home, killing at least seven residents. All 10 of the deaths so far have been reported in the last few days.

An Amazon employee in Seattle has contracted the novel coronavirus — the first employee among its US workforce to fall ill with COVID-19, the company said.

The e-commerce giant on Tuesday told employees in an email about the infected employee, who works at Amazon's South Lake Union office complex, where the company's headquarters are located, Bloomberg reported. It was not immediately clear how the employee contracted the virus.

The region's medical resources are "under incredible stress right now", said Patty Hayes, director of public health for Seattle and King County. "We need to slow the spread of disease to the point where our healthcare system can continue to handle the load."

There are at least 138 confirmed coronavirus cases in the US, and the number was expected to rise this week as the Centers for Disease Control and Prevention (CDC) on Wednesday broadened guidelines for coronavirus testing, allowing doctors to order a test for any patients who have symptoms such as fever, cough or difficulty breathing.

The new standard greatly expands the pool of patients who qualify for testing, but laboratory capacity available to process the tests remains limited.

In New York, Governor Andrew Cuomo announced four new confirmed cases Wednesday, raising the state's total number of cases to six. The wife and two children of a 50-year-old male resident of Westchester County who was diagnosed with the virus on Tuesday have tested positive. A neighbor who drove the man to the hospital also tested positive, Cuomo said.

The first major step by Congress to tackle the coronavirus threat in the US came in a 415-2 vote just hours after lawmakers in both chambers struck the bipartisan deal for emergency funding. The Senate is expected to take up the measure this week and then send it to President Donald Trump for signing.

The bill provides $7.76 billion to agencies combating the coronavirus — three times the $2.5 billion initially requested by the White House in late February.

It also authorizes roughly $500 million to allow Medicare providers to administer telehealth services so that more elderly patients, who are at greater risk from the virus, can receive care at home, bringing the total to about $8.3 billion.

The US airline industry has been in the spotlight since the outbreak as the government has restricted travel to select countries, but not domestically.

On Wednesday, however, United Airlines became the first US carrier to cut domestic flights. United said it would cut domestic and international routes in April in response to the slump in travel demand caused by the spreading coronavirus.

Domestic capacity will be cut by 10 percent next month from its previous plan, and international flying will be cut by 20 percent, CEO Oscar Munoz and President Scott Kirby said in a message to staff. The cuts could extend into May.

Among US carriers, United has the largest exposure to international markets, and half the cuts will be on trans-Pacific routes.

The carrier is also parking some wide-body jets and offering staff members unpaid leaves of absence in the latest effort by airlines to mitigate the impact of virus-related travel restrictions and passenger concerns over flying.

On Wednesday morning, Trump made a surprise appearance at a meeting Vice-President Mike Pence was holding with US airline CEOs to discuss precautions the carriers were taking to combat the coronavirus outbreak, including new cleaning procedures.

Asked for his message to Americans about whether they should be afraid to travel, Trump gestured to the airline chief executives and said: "I think where these people are flying, it's safe to fly," adding that if certain areas begin to be more of a problem, "we may close them up".