Tokyo Angered by U.S. Sub's Surprise Docking

T O K Y O, April 4 -- Two months after the USS Greeneville accidentally surfaced beneath and struck a Japanese fishing boat, another American submarine has upset officials in Tokyo.

Japanese bureaucrats officially expressed their displeasure today after a U.S. submarine entered into a southwestern Japanese port without giving advance notice.

U.S. military officials had informed the Sasebo City government that the nuclear submarine Chicago would anchor outside the port on Monday for a routine port call.

But the 6,080-ton sub unexpectedly entered the port for about 20 minutes before leaving, he said today.

Violating ‘Established Practice’

The brief stop violated a 1964 bilateral accord requiring the United States to notify Japan 24 hours in advance of port calls for U.S. nuclear-powered submarines.

The notice gives time for local authorities to check radioactivity levels in ports before and after U.S. submarine visits.

"There is an established practice. When it comes to the entry of the U.S. submarine into the Japanese port to notify 24 hours prior to the entry of the ship into the Japanese port," said Norio Hattori, press secretary for Japan's Ministry of Foreign Affairs.

Relations between the United States and Japan have been strained in recent months.

A string of crimes by U.S. military personnel and the sinking of a Japanese fishing boat by the U.S. Navy submarine Greeneville in February have been a source of friction between the two countries.

There are nearly 50,000 U.S. troops stationed in Japan.