North Korea recently deployed a new type of medium-range ballistic missile capable of reaching northern Australia and the US territory of Guam, South Korea's Defense Ministry said Monday. The report comes amid speculation that the isolated regime also is preparing to test-fire another, longer-range missile capable of hitting Alaska. The new intermediate-range ballistic missile can travel at least 1,800 miles, which would put the Pacific island of Guam, the northern tip of Australia and much of Russia and India within striking distance, the ministry said in a report. It did not offer any other details on the new missile, including exactly when or how many missiles have been deployed and where their launching grounds are located. The new missile is believed to be the same type displayed at a military parade in North Korea in 2007. The communist nation has been developing the missile since the late 1990s, according to a defense assessment on North Korea issued by the South every two years. Pyongyang is also believed to be preparing to test-fire a version of its longest-range ballistic missile, the Taepodong-2, amid heightened tension with Seoul. Relations have been tense since President Lee Myung-bak took office a year ago in South Korea, calling on the North to honor its commitment to disable its nuclear program. Media reports say the missile being readied for launch could be an advanced version of the Taepodong-2 that could reach even farther than Alaska and strike the US west coast. North Korea's missile program is a major security concern for the region, along with its nuclear weapons development. The country test-launched a Taepodong-2 missile in 2006, but the rocket plunged into the ocean shortly after liftoff. That test alarmed the world and gave new energy to the stop-and-start diplomacy over North Korea's nuclear program, though Pyongyang is not yet believed to have mastered the miniaturization technology required to put a nuclear warhead on a missile. North Korea has also shorter-range Scud and Nodong missiles capable of hitting neighboring South Korea or Japan. South Korea is the most likely target of Scuds, which have a range of up to 310 miles, while Japan is the likely focus for Nodongs. The North is believed to have more than 1,000 Nodong and Scud missiles in its arsenal. The defense report also noted an increase in troops in North Korea. About 180,000 of the North's 1.19 million troops are special warfare forces trained for nighttime, mountain and street fighting - up from 120,000 reported two years ago, it said. The move shows the North is prepared for various types of attacks on the South in case of war, the report said. On Pyongyang's nuclear capability, the report said the North is believed to have secured about 88 pounds of plutonium - nuclear weapons fuel - and conducted an atomic test in 2006. It did not give an estimate of the number of atomic bombs North Korea has, dropping a reference from a previous report that said Pyongyang, which wants to be recognized as a nuclear power, is believed to have built one or two nuclear weapons.