(CNN) -- The U.S. government is asking Americans who have travel plans to Japan to reconsider for now.
The U.S. Department of State has issued a travel alert strongly urging U.S. citizens to avoid tourism and nonessential travel to the country for the next few weeks as it deals with the massive earthquake that struck Friday.
"Tokyo airports are currently closed; other airports in Japan may be closed or have restricted access," the agency said in a statement.
"Public transportation, including trains and subways, are closed in the Tokyo area, and service has been interrupted in other areas. Many roads have been damaged in the Tokyo area and in northern Japan," it said.
Strong aftershocks are likely for weeks following a strong earthquake such as this one, the agency notes. The travel alert expires on April 1.
Japan has long been a popular tourist destination for Americans. More than 727,000 visited the country last year, according to the Japan Tourism Marketing Co.
If you have plans to travel to the region, many airlines are making it easier for you to postpone your flight.
American Airlines, Delta and United have issued travel waivers for passengers flying to, from or through Japan in the next several days. The waivers will allow travelers to change their plans without a fee.
Meanwhile, Japan's Al Nippon Airways says its flights to and from Tokyo's Narita International Airport may be delayed, canceled or diverted. The carrier is asking passengers to check the status of their flight online.
Cathay Pacific reports that it is likely its flights to Japan will be affected for days.
The U.S. Department of State is urging American citizens already in Japan to contact family and friends in the United States as soon as possible to let them know they're safe.
The government also has set up a special e-mail address for U.S. citizens to contact the Department of State: JapanEmergencyUSC@state.gov.
For updated information on travel and security in Japan, you can call the Department of State at 1-888-407-4747. The number is toll-free in the United States and Canada. CNN
