The White House has told airline executives it’s considering suspending flights from China to the U.S. amid an escalating outbreak of a new coronavirus that has infected thousands of people across the world, people familiar with the matter said.

The Trump administration is looking at a variety of measures to contain the fast-spreading virus that has infected roughly 4,700 people across the globe, U.S. health officials told reporters on a conference call Tuesday. White House officials called executives at major U.S. carriers on Tuesday, telling them that a temporary ban on China flights is on the table, according to people familiar with those conversations.

United Airlines, which has the most service of the U.S. airlines to Hong Kong and mainland China with about a dozen daily flights, on Tuesday announced it would cancel dozens of flights next month to Hong Kong and mainland China as the outbreak worsens. The Chicago-based airline said it has experienced a “significant decline in demand for travel to China.” United and its rivals Delta and American are waiving cancellation and change fees for travelers booked to China.

The restrictions could affect flights into and out of China, as well as airports across the United States, administration officials said. They declined to be named because no final decision has been made.

A senior staff meeting was held at the White House on Monday during which the restrictions were discussed.