North Korea this week announced it carried out its first-ever nuclear test. North Korean officials said they exploded a nuclear weapon under the ground.

International testing equipment confirmed that ground movement in the northeastern part of the country suggested a nuclear explosion. Other nations are still working to confirm the reported test.

For many observers, the North Korean announcement came as no surprise. They say the country's effort to develop a nuclear weapon began many years earlier.

Intelligence reports showed that North Korea had the materials needed to make such a weapon in the early nineteen nineties. In nineteen ninety-four, North Korea offered to suspend its nuclear program as part of an agreement with the United States. In exchange, North Korea was offered large amounts of fuel oil and help in building two nuclear reactors for electricity.

Six years ago, North Korea asked the United States to pay for delays in the reactor project. It also threatened to withdraw from the nineteen ninety-four agreement.

President Bush took office in two thousand one. His administration decided to re-examine relations with North Korea. The administration said it was not sure if the North would honor the agreement.

Later, Mister Bush identified North Korea, Iran and Iraq as what he called the axis of evil. He also said the North was arming itself with missiles and weapons of great destruction, while starving its citizens.

Four years ago, the United States said North Korea admitted to having a secret weapons program. It said the program violated the nineteen ninety-four agreement. The international group building the reactors said it was halting oil exports to North Korea.

The country answered the announcement by re-opening its nuclear center in Yongbyon. Within a year, North Korea had expelled international nuclear inspectors, and withdrawn from the Nuclear Non-Proliferation Treaty. The treaty was created to prevent the spread of nuclear weapons.

To ease tensions, North Korea opened disarmament talks with the United States and four other nations three years ago. Last September, they released a joint statement. It said North Korea would end its nuclear arms program in exchange for economic aid and security guarantees.

North Korea later said it would not return to the talks unless American financial restrictions are lifted. The restrictions are meant to punish the North for its reported involvement in illegal activities.

North Korea says it needs nuclear weapons to prevent an attack by the United States. But America has repeatedly said it has no plans to attack the North. It has urged the country to act on its earlier offers to not build nuclear weapons.

President Bush said Wednesday that the United States supports diplomacy to settle the nuclear issue. But he rejected calls to open direct talks with North Korea.

IN THE NEWS, in VOA Special English was written by Brianna Blake. I'm Steve Ember.