South Koreans will have to undergo extra screening before they can be escorted onto U.S. bases in Japan, as will people from North Korea, China and Russia, the U.S. military newspaper Stars and Stripes reported Monday.

"The U.S. military has ordered extra scrutiny for South Koreans who want to visit friends or attend events on American bases in Japan," the daily wrote.

The U.S. Forces Japan "recently added the longtime American ally to a list of nations whose citizens must undergo additional screening before they can be escorted onto installations," it added.

South Korea was put on the list alongside about 50 other nations including Iran and Afghanistan. The USFJ did not give a reason for the new checks on South Koreans, but there is speculation that it has something to do with a recent change in the U.S. military's perception of South Korea.

The U.S. restricts access to its bases around the world, to guard against leaks, espionage and terrorism. The U.S. Forces Korea, for example, bans all North Koreans and Iranians from its bases.

A sign near the main entrance to the USFJ's main base says, "No personnel will escort a designated third-country national onto Yokota Air Base. It is the responsibility of the escort sponsor to verify the individual is not from one of the... designated countries."

Only a month ago, South Koreans could enter U.S. installations in Japan after a simple process if they were escorted by a U.S. officer or had an official invitation. But now USFJ spokeswoman Genieve White recommended that "sponsors contact security forces 30 days ahead of a planned visit."

A USFK officer here said there is no information about South Koreans committing crimes against U.S. military personnel in Japan.

