The United States expressed deep concern about North Korea’s vulnerability to the outbreak of a new virus and said it was ready to support efforts by aid organizations to contain the spread of the illness in the country.

Pyongyang has moved to strengthen quarantines and other preventive measures after the illness outbreak in China, North Korea’s neighbor and closest ally.

“We strongly support and encourage the work of US and international aid and health organizations to counter and contain the spread of coronavirus” in North Korea, State Department spokeswoman Morgan Ortagus said. “The United States is ready and prepared to expeditiously facilitate the approval of assistance from these organizations.”

North Korea’s media have described the fight against the illness as a matter of “national existence.” It has shut down nearly all cross-border traffic, banned foreign tourists, intensified screening at entry points and mobilized some 30,000 health workers to monitor residents, AP said.