The US State Department issued an updated travel warning on Sunday that urges American citizens to avoid going to Japan because of the powerful earthquake two days ago.
The department said it requested all non-essential US government personnel to defer travel and urged American citizens to avoid tourism and non-essential travel to Japan.
It said that strong aftershocks were likely for weeks after a powerful earthquake such as the one that struck northern Japan.
Flights have resumed at all airports closed by the earthquake, except for the airport in the coastal city of Sendai, which remains flooded, the department said.
In Tokyo, most public transportation including trains and subways was operating, the department said.
But many roads have been damaged in the Tokyo area and in northern Japan. In the far-northern Iwate prefecture, toll road highways are restricted to emergency vehicles only, it said. - Reuters