WASHINGTON (Yonhap) ― The U.S. Army’s troop reduction, driven by budget constraints, could ultimately affect South Korea, even though American troops levels in the Asian ally will remain the same in the first round, an Army official said Thursday.

Earlier in the day, the Army announced force structure decisions and stationing plans that call for a reduction of the regular Army from 490,000 to 450,000 soldiers in fiscal years 2016 and 2017. The reduction of 40,000 will be completed by the end of fiscal year 2018, it said.

The troop reduction is driven by automatic spending cuts requirements known as “sequestration.”

The Army further warned that unless the budget constraints are addressed, the next round of troop cuts will leave the Army with only 420,000 soldiers by the end of fiscal year 2019.

“Troop levels in Korea remain the same for now. However, the next round of cuts (down to 420,000) may impact South Korea,” Lt. Col. Joe Buccino, an Army spokesman, told Yonhap News Agency.

Currently, about 28,500 American troops are stationed in South Korea to help deter threats from North Korea, a legacy of the 1950-53 Korean War that ended in a truce, not a peace treaty, which left the divided peninsula still technically at war.

Cdr. Bill Urban, a Pentagon spokesman, said the first round of cuts in the next two years “will not affect troop strength levels in the Republic of Korea.” He said the Army force structure cuts were first announced in February when President Barack Obama submitted the defense budget to Congress.

Should the Army troop levels drop to 420,000 by 2019, it would mean “a cumulative loss of 150,000 soldiers from the regular Army, a 26 percent cut over a seven-year period,” the Army warned in the announcement.

“The resulting force would be incapable of simultaneously meeting current deployment requirements and responding to the overseas contingency requirements of the combatant commands,” it said.