North Korea made the final preparations to launch a multistage rocket today, raising international tensions and sending worries through its nearest neighbor, Japan.

The communist state scrambled MiG-23 fighter-jets to its east coast near the missile launch site and warned that it would attack major targets in Japan if Tokyo shot the missile down, according to South Korean media reports.

This, as the country could start countdown as early as Saturday morning. North Korea officially says its rocket will blast off sometime between Saturday and next Wednesday.

I think it's almost certain North Korea will fire the missile,” South Korea President Lee Myung-bak said Friday in London.

President Obama criticized the launch as a provocative act that would violate a United Nations resolution. The leaders of Japan and South Korea agreed in London that if it occurred, it should be addressed by U.N security Council.

North Korea says it is launching an experimental communications satellite and the launch is part of peaceful research, but U.S. and its allies see the test as a provocative demonstration of a long-range ballistic missile that could fly as far as the western United States.

Neighboring governments were on heightened alert on Friday, with the U.S, South Korea and Japan they have dispatched ships with anti-missile systems to monitor the launch.

It's too early to say for sure whether the object the North is launching is a satellite or a missile, our principled position is that it threatens peace and stability on the Korean Peninsula, said Lee Jong-joo, a government spokesman in Seoul.

Last week, Japan ordered land and sea-based antimissile system to destroy debris from the North's missile if it failed in flight and fell on Japan.

North Korea has about 200 midrange Nodong missiles that are capable of striking nearly every part of Japan, according to the Defense Ministry in Tokyo.

Although North Korea is one of the poorest countries in Asia, it has made itself into the greatest supplier of missiles, missile components and related technologies in the developing world, according to a 2008 U.S. Army report.

North Korea for the first time launched the Taepodong-2 missile in a a test failed in 2006 when it blew apart 40 seconds after launching.