The United States declared Friday that it will not produce or acquire any antipersonnel land mines and is pursuing other steps toward eventually signing a 1997 treaty banning the weapons.

At the conclusion of a conference in Maputo, Mozambique, to review the Mine Ban Treaty, also known as the Ottawa Convention, the U.S. delegation said the ban on production or acquisition of the antipersonnel land mines, or APLs, will also prevent the United States from replacing existing stockpiles as they expire.

“Our delegation in Maputo made clear that we are diligently pursuing solutions that would be compliant with and ultimately allow the United States to accede to the Ottawa Convention — the treaty banning the use, stockpiling, production and transfer of APL,” National Security Council spokeswoman Caitlin Hayden said in a statement.

The administration is studying how to reduce the risks of forgoing land mines, and “other aspects of our land-mine policy remain under consideration,” she said.

“The United States shares the humanitarian goals of the Ottawa Convention and is the world’s single largest financial supporter of humanitarian mine action, providing more than $2.3 billion in aid since 1993 in more than 90 countries for conventional weapons destruction programs,” Hayden said.

The U.S. statement to the Maputo conference, which drew more than 1,000 participants from around the world, was delivered by Douglas M. Griffiths, the U.S. ambassador to Mozambique. The country has a history of land-mine use and casualties dating from decades of warfare that ended in 1992. It has been a focus for years of international efforts to clear land mines.

Advocates of a global ban on land mines welcomed the U.S. declaration but said the Obama administration did not go far enough toward getting rid of the weapons, which kill or maim an estimated 4,000 people a year in dozens of countries where they have been planted and often forgotten.

“The U.S. statement from Maputo is useful in that it underscores land mines are not essential to U.S. security and are on their way out, but it falls short of what can and should be done,” Daryl G. Kimball, executive director of the Washington-based Arms Control Association, said in a statement. He noted that the United States already had no plans to produce antipersonnel mines barred by the treaty and that the Pentagon is carrying out no research and development on the weapons.

“Without a commitment to destroy some or all of the United States’ existing stockpile of land mines and on a schedule, the pledge not to produce or acquire land mines will have little material effect on existing U.S. stockpiles for many, many years to come,” Kimball said. Unless the Obama administration changes course, he added, the 2004 policy of the George W. Bush administration remains in effect, “permitting the indefinite use of self-destructing, self-deactivating antipersonnel mines anywhere in the world.”

The administration’s commitment Friday to study military alternatives to land mines as part of a goal of eventually signing the Mine Ban Treaty is also “positive,” Kimball said, “but the failure of President Obama to provide more decisive and prompt leadership on this issue is disappointing.” An administration policy review on land mines, underway since November 2009, has taken far too long, and no deadlines have been set for completing either the review or the study on alternatives, Kimball said.

More than 160 nations have signed the Mine Ban Treaty, which prohibits the use, development, production, stockpiling or transfer of antipersonnel land mines. They weapons are defined as explosives designed to be detonated by “the presence, proximity or contact” of people. Land mines that are command-detonated or that target vehicles are not banned.

The United States has not used land mines since 1991, although it is estimated to maintain a stockpile of more than 9 million of the weapons.

Under previous administrations, U.S. officials have sought to explain the refusal to join the treaty by drawing a distinction between so-called “smart” land mines, which are allowed by U.S. policy because they can be set to self-destruct or deactivate automatically, and “dumb” mines, which can detonate many years after being planted. Officials have said that smart mines might be needed to protect U.S. troops from being overrun by enemies.

Besides the United States, 35 countries have not acceded to the Mine Ban Treaty. They include Russia, China, India, Pakistan, Burma, and North and South Korea.

Stephen Goose, co-founder of the International Campaign to Ban Landmines and a participant at the Maputo conference, told the Associated Press that Friday’s announcement represents progress because the United States has always reserved the right to produce more land mines. He also welcomed the nation’s intention to join the treaty, although he noted that there is no guarantee or timeline to do so.

Goose said the United States should at least set a target date to join the treaty, immediately pledge not to use land mines and begin destruction of its stockpiles.

“It gives us great relief that the U.S. is banning the production of these deadly weapons,” Elizabeth MacNairn, executive director of Handicap International U.S., said in a statement. “To hear them speak about accession to the treaty as a foreseeable goal is a cause for celebration.”

But she, too, complained about the administration’s failure to set deadlines, saying that the United States “runs the risk of allowing its land-mine policy review to drift beyond President Obama’s term in office.” MacNairn said the U.S. declaration Friday “also fell short by not committing to a full ban” on the use of antipersonnel land mines.