US President Donald Trump attends a press conference in the White House in Washington D.C., the United States, on Feb. 26, 2020. US President Donald Trump on Wednesday appointed Vice President Mike Pence to oversee the country's response to the novel coronavirus outbreak. (Xinhua/Liu Jie)

The Washington State Department of Health confirmed the first death in connection with coronavirus disease 2019 (COVID-19) Saturday as more cases of unknown origin were reported in western US states.

One person has died from COVID-19 in King County, Washington, making his/her death the first such case in the United States, health officials said.

The department made no further details about how the victim contracted the virus. President Donald Trump said later in a press briefing Saturday afternoon that the victim is a woman in her late 50s.

Washington Governor Jay Inslee said "it is a sad day in our state as we learn that a Washingtonian has died from COVID-19."

"In partnership with the Washington State Department of Health, the Washington State Department of Emergency Management and local and community health partners, we are strengthening our preparedness and response efforts," he said.

Washington health officials announced two new cases of COVID-19 in the state Friday night. The two patients are a student at Jackson High School in Mill Creek and a King County woman in her 50s, who recently traveled to Daegu, South Korea.

Washington reported the first COVID-19 case of the United States last month after a man in his 30s from Snohomish County tested COVID-19 positive following his return from China's Wuhan city.

As the number of COVID-19 cases increased globally, more cases of the coronavirus disease of unknown origin have been reported in US western states, triggering concern about local person-to-person spread of the infectious disease.

The Santa Clara County of California reported a second COVID-19 case of unknown origin in the United States on Friday, while Oregon Health Authority said an elementary school employee tested coronavirus positive, though the person had no travel history nor close contact with infected individuals.The Oregon patient is the state's first "presumptive" COVID-19 case ever reported.

Trump said the United States currently has 22 confirmed COVID-19 cases, while data from the Centers for Disease Control and Prevention showed that there have been three cases of person-to-person transmission. There are also 47 infected people who evacuated from either Wuhan city or the Diamond Princess cruise ship docked in Japan.