South Korea and the United States have agreed that U.S. troop strength in the Asian country will be reduced at a much slower pace than originally announced. The change came after intense pressure from Seoul.

In simultaneous announcements in Seoul and Washington Wednesday, the two allies said the deadline for withdrawing more than 12,000 U.S. troops from South Korea has been extended to 2008. That is three years later than originally planned, although still reportedly several years faster than Seoul desired.

South Korea raised concerns about the original U.S. plan to cut a third of its troop strength in the country by next year, given the heightened tensions caused by North Korea's nuclear weapons programs.

International Studies Professor Paik Jin-hyun of Seoul National University says the majority of South Koreans feel American forces are vital to their country's security.

"Many Koreans are very much worried about the consequence of such a plan. I think the Korean government, quite rightly, asked the United States to reconsider the plan to reduce its forces rather radically," he said.

The United States also agreed to reverse a decision to remove multiple-launch rocket system batteries and Apache attack helicopters deployed near the border between the two Koreas.

Wednesday's joint statement says South Korea considers those elements to be "vital to maintain war-deterrence capability against North Korea."

Those batteries would be able to respond to an attack by an estimated one-thousand long-range North Korean artillery pieces believed capable of hitting Seoul from about 50 kilometers away.

Officials in Seoul say the first phase of the withdrawal will see some 5,000 troops leaving this year. During the second phase, about 3,000 troops will leave next year, and 2,000 more in the year 2006.

In the final phase, during 2007 and 2008, an additional 2,500 troops - mainly support units - will be redeployed.

The total of 12,500 troops to be redeployed include members of the 2nd Brigade Combat Team who were already sent from South Korea to Iraq in August.

U.S. military officials say the troop reductions will not weaken their ability to respond to any North Korean aggression. They note that $11 billion have been allocated to increase U.S. firepower in South Korea over the next few years.

The troop drawdown is part of a new global strategy by the United States to reduce and realign its overseas military presence. Large, fixed overseas bases were built as a deterrent against the former Soviet Union and its communist allies during the Cold War era.