TOKYO -- The commander of American troops in Japan said Thursday that the situation ahead of North Korea's planned launch of a long-range rocket this month is "very dangerous."

Lt. Gen. Salvatore Angelella said U.S. troops in Japan are closely monitoring activity in North Korea as it prepares for the launch. He said the United States sees the launch as a violation of U.N. restrictions in place to keep North Korea from developing its long-range missile capabilities.

"This is a very dangerous situation, and we do not support those actions by North Korea. ... We are monitoring the situation closely," Angelella, who commands the roughly 50,000 U.S. troops in Japan, said at a news conference in Tokyo.

He said American troops are working closely with the Japanese to protect the country's citizens and territory, but declined to give details. Two U.S. officials said Wednesday that the Navy had begun moving several ships into the western Pacific.

North Korea has announced it will launch the rocket between Dec. 10 and 22. It attempted a similar launch in April, but it failed shortly after liftoff.

Also on Thursday, a Japanese man who served as a chef to the North Korean leadership and visited the country earlier this year said the planned rocket launch was meant to honour the late leader Kim Jong Il.

Kenji Fujimoto, Kim's personal sushi chef from 1988-2001, said he believes the late leader's son and successor, Kim Jong Un, was backing the launch to show respect for his father.

"I don't think that Kim Jong Un is taking a very aggressive role in pushing for this launch, but he might want to commemorate his father's passing," said Fujimoto, who uses a pseudonym.

He said that despite its apparent determination to defy international appeals against the rocket launch, he believes North Korea is changing for the better and wants to improve relations with the West.

Fujimoto settled in Japan after leaving the North Korean capital, Pyongyang, and has written several memoirs. The latest is about a visit to North Korea for several weeks last summer.

That trip was meant to fulfil a promise he had made to the younger Kim before he left, he says.

Fujimoto says that during his years as Kim Jong Il's chef, he got to know Kim Jong Un and other members of the family, and that his reunion with the current North Korean leader was an emotional one. A photo on the cover of his latest book purports to show Kim Jong Un embracing Fujimoto.