The outbreak is disrupting demand for flights and many airlines have suspended or modified services in response. After Saturday's press conference, the White House held a call with airlines to discuss new travel restrictions.
Leaders in Europe, the Middle East and the Americas rolled out bans on big gatherings, and stricter travel restrictions as cases of the new coronavirus spread around the world.
US on Saturday reported its first death from the disease, a Washington state man in his 50s. Two of the state's three cases have links to a nursing home, state officials said, where dozens of residents have symptoms of the disease.
US President Donald Trump and top officials said in a White House press briefing that travellers from South Korea and Italy would be subject to additional screening, and warned Americans against travelling to coronavirus-affected regions in both countries.
US Vice President Mike Pence said a ban on travellers from Iran entering the country would be expanded to include any foreign nationals who have visited Iran in the last 14 days.
US may also restrict travel on its southern border with Mexico, officials said.
However, they encouraged Americans to travel around the country, including to states where some of the country's more than 60 cases of the disease have been recorded.
American Airlines Inc said late on Saturday it was suspending all US flights to Milan.
Ecuador on Saturday reported its first case, in a woman who had travelled from Madrid, while Mexico reported four cases, all in people who had visited Italy.
Brazilian officials confirmed that country's second case, a patient in Sao Paulo who recently visited Italy.
As governments worldwide stepped up efforts to halt the spread of the virus, France announced a temporary ban on public gatherings with more than 5,000 people in confined spaces. It reported 16 new cases for a total of 73, and cancelled a half-marathon of 40,000 runners scheduled for Sunday.
Switzerland said it is banning events expected to draw more than 1,000 people.
More than 700 tourists remain quarantined at a hotel in the Canary Islands, after several Italian guests there tested positive for coronavirus.
Schools and universities in Italy, which is experiencing Europe's worst outbreak of the disease, will stay closed for a second consecutive week in three northern regions. The country has reported more than 1,100 cases and 29 deaths.
Analysts have warned that the outbreak looks set to shunt Italy's fragile economy into its fourth recession in 12 years, with many businesses in the wealthy north close to a standstill and hotels reporting a wave of cancellations.
Focus on Iran
Iraq reported five new cases of the disease, bringing its total to 13, and Qatar reported its first on Saturday, leaving Saudi Arabia as the only Gulf state not to have signalled any coronavirus cases.
The majority of infections in other Gulf countries have been linked to visits to Iran or involve people who have come into contact with people who had been there.
Tehran has ordered schools shut until Tuesday and extended the closure of universities and a ban on concerts and sports events for a week. Authorities have also banned visits to hospitals and nursing homes as the country's caseload hit nearly 600.
One Iranian lawmaker, elected in February 21 polls, has died from the disease along with more than 40 other Iranians, and several high-ranking officials have tested positive for the virus.
Azerbaijan said on Saturday it had closed its border with Iran for two weeks to prevent the spread of coronavirus. Two Azerbaijanis who travelled to Iran have tested positive for the disease and quarantined.
Mainland China reported 573 new confirmed coronavirus cases on February 29, up from 427 on the previous day, the country's health authority said on Sunday morning in China. The number of deaths stood at 35, down from 47 on the previous day, and bringing the total death toll in mainland China to 2,870.
The epidemic, which began in China, has killed almost 3,000 people worldwide, the ministry said.