The U.S. State Department on Thursday raised its travel alert for China to the highest level over the outbreak of a new coronavirus there, urging its citizens not to visit the country.

The department increased its China travel advisory to level 4, or "Do not travel," from level 3, or "Reconsider Travel."

Secretary of State Mike Pompeo attributed the move to the spread of the virus throughout China and the World Health Organization's decision the same day to designate the outbreak a Public Health Emergency of International Concern.

"Those currently in China should consider departing using commercial means," the State Department said.

The department on Wednesday authorized the departure of family members and all non-emergency U.S. government employees at its embassy in Beijing and consulates general in four cities in China including Shanghai, a spokesperson said earlier Thursday.

The decision was made "out of an abundance of caution related to logistical disruptions stemming from restricted transportation and availability of appropriate health care related to the novel coronavirus," the spokesperson said.

The three other consulates general are in Chengdu, Guangzhou and Shenyang. Family members and non-emergency employees of the U.S. Consulate General in Wuhan, the epicenter of the virus outbreak, were ordered to evacuate earlier.

The United States, meanwhile, confirmed its first person-to-person transmission of the pneumonia-causing virus, the country's health protection agency said Thursday.

The patient in the Midwest state of Illinois is the husband of a woman in her 60s already confirmed to have been infected with the virus. The woman returned to the United States from Wuhan on Jan. 13 and later developed symptoms.

At a briefing, the Centers for Disease Control and Prevention emphasized that "this spread was among two people who were in close contact for an extended period of time" and that the institution believes "the immediate risk to the American public is low."

The latest case brings the total number of confirmed infected individuals in the United States to six.

The couple live together and the man had been in contact with his wife since her return to the United States. Investigations have shown so far that the man did not attend any mass gatherings prior to being hospitalized, the agency said.

It also indicated that he is in "stable" condition, while his wife is doing "quite well" as she recovers from the illness.

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