EMBED >More News Videos The first case of novel coronavirus was confirmed in Orange County Saturday, health officials said.

EMBED >More News Videos Public health officials on Sunday confirmed the first case of novel coronavirus in Los Angeles County, making it the fourth case of the strain in the United States.

EMBED >More News Videos ABC News' Dr. Jen Ashton explains what health officials know -- and don't know -- about the deadly outbreak.

ONTARIO, Calif. (KABC) -- A chartered jet carrying U.S. consulate employees from China is set to land in Southern California this week. The travelers are expected to take off Wednesday from Wuhan, the center of the coronavirus outbreak, and land at Ontario International Airport.The employees were ordered to leave China and head to the U.S. by the State Department, a State Department spokesperson told Eyewitness News.Officials say the passengers will go through three health checks to determine if any of them are infected with the coronavirus, which has already claimed dozens of lives in China.The consulate employees are returning on an order from the U.S. State Department. Depending on available space, some U.S. citizens may also board the flight, according to a department spokesperson.The Ontario airport, meanwhile, is expected to proceed with normal operations."The safety and security of our facilities are of utmost importance to ONT, and we are taking whatever steps are necessary to minimize the risk to our customers, our staff and the community at large," airport officials said in a written statement.Meanwhile, the Trump administration is being urged to declare a formal public health emergency.Five people in the United States have been diagnosed with coronavirus, including one person each in Los Angeles and Orange counties.