The United States is limiting its use and stockpiling of landmines outside the Korean Peninsula, but will not join more than 160 other nations who signed a total ban on the weapons, citing the threat from North Korea, the Obama administration said Tuesday.

“This means that United States will not use [anti-personnel landmines, or APL] outside the Korean Peninsula; not assist, encourage, or induce anyone outside the Korean Peninsula to engage in activity prohibited by the Ottawa Convention; and undertake to destroy APL stockpiles not required for the defense of the Republic of Korea,” National Security Council Spokeswoman Caitlin Hayden said in a statement.

Pentagon Press Secretary Rear Adm. John Kirby said the Defense Department would begin the destruction of all landmines “not required for the defense of South Korea.”

The policy change builds on a commitment by the administration in June to stop the manufacture, acquisition or replacement of existing stocks of landmines. But the U.S.—like its ally in Seoul—has abstained from signing the weapons ban citing what State Department Spokeswoman Jen Psaki called the “unique situation” of the Demilitarized Zone that separates North and South Korea.

(Read More: A Good Step Toward Ending Landmines)

“Many countries use landmines irresponsibly, but the United States is not one of them. In fact, the over 400,000 mines in our inventory all either self-destruct or self-deactivate,” said Rep. Buck McKeon, R-Calif., chairman of the House Armed Services Committee, and Rep. Randy Forbes, R-Va., chairman of the Subcommittee on Seapower and Projection Forces, in a June statement. “The cost to replace our mines in areas where they are essential to our defense and that of our allies, like the Korean Peninsula, will run into the hundreds of millions. The cost of an alternative defensive platform could be billions more.”

In March, Joint Chiefs Chairman Gen. Martin Dempsey told the House Armed Services Committee that self-destructing landmines were “an important tool in the arsenal of the armed forces of the United States.”

The U.S. has provided more than $2 billion for the destruction of conventional weapons in nearly 100 countries. Still, the charity organization Handicap International says the U.S. has taken a “vague position” on landmines since the ban first went up for a vote nearly two decades ago. U.S. reluctance to sign the mine ban treaty, the group said in June, “could serve as carte blanche for other major powers, such as China and Russia, to remain on the sidelines of this life-saving treaty.”

The nonproliferation group Arms Control Association estimates approximately 100 million mines are still planted in the ground in 59 different countries. More than 30 countries have still not signed the mine ban treaty, including much of the Middle East as well as UN Security Council members China and Russia.