South Korea is preparing for next week's visit by new Secretary of State Hillary Clinton, as Northeast Asia contends with the prospect of a possibly imminent North Korean missile launch.  Senior South Korean officials say the country is stepping up its missile defenses, and warn Pyongyang it has nothing to gain by saber rattling.

South Korean Prime Minister Han Seung-soo told lawmakers in Seoul Friday the country is on alert amid signs North Korea may be preparing to test launch a long range missile.

He said the South is responding to the possibility of a launch by boosting its anti-ballistic missile defenses.

The South's chief official on North Korea policy,  Unification Minister Hyun In-Taek, said Seoul is being vigilant.

He said South Korea is closely watching the movements of North Korean troops and is making thorough preparations for all situations.

South Korean and U.S. experts have warned there is evidence North Korea is preparing a launch site.  South Korea's largest daily newspaper, the Chosun Ilbo, quoted intelligence officials who said the North is transporting rocket sections to the site.

South Korean Foreign Minister Yu Myung-hwan warned this week, Pyongyang is miscalculating the advantages of provoking its neighbors - and could trigger punitive action by the United Nations.

Yu said a missile test will not benefit North Korea at all.

Over the past year, Pyongyang has steadily sharpened its rhetoric against conservative South Korean President Lee Myung-bak.  The North also warned last month it was scrapping all previous peace accords with the South.

Yong-hyun Kim is a North Korea specialist at Seoul's Dongkuk University.  He said North Korea may be following in its past past footsteps of using a military display for political objectives.

He said North Korea's provocative actions are intended to get the attention of the United States. Pyongyang also hopes to rally North Korea's public, he said, by pressuring South Korea - all the while trying to rattle the resolve of the Lee administration.

Monday marks the first-time arrival in Asia of U.S. Secretary of State Hillary Clinton since taking the position.  It is also the 67th birthday of North Korean leader Kim Jong Il.  While that date might possibly be seen by the North as an auspicious one for the launch, many experts believe Pyongyang will not be technically capable of conducting a long-range missile test before the end of the month.