* U.S. to send observers to conference on Mine Ban Treaty
* 10-year-old accord has been endorsed by 156 countries
* Treaty bans stockpiling, use of antipersonnel mines
By David Alexander
WASHINGTON, Nov 24 (Reuters) - President Barack Obama has no plans to join a global treaty banning landmines because a policy review found the United States could not meet its security commitments without the weapons, the State Department said on Tuesday.
"This administration undertook a policy review and we decided that our landmine policy remains in effect," spokesman Ian Kelly told a briefing five days ahead of a review conference in Cartegena, Colombia, on the 10-year-old Mine Ban Treaty.
"We determined that we would not be able to meet our national defense needs nor our security commitments to our friends and allies if we signed this convention," he said.
It was the first time the administration had publicly disclosed the decision.
The Mine Ban Treaty, which went into force on March 1, 1999, bans the use, stockpiling, production or transfer of antipersonnel mines. It has been endorsed by 156 countries, but several powers -- including the United States, Russia, China and India -- have not adopted it.
Landmines are known to have caused 5,197 casualties last year, a third of them children, according to the Nobel Prize-winning International Campaign to Ban Landmines (ICBL), which links some 1,000 activist groups.
The United States generally abides by the provisions of the treaty. It hasn't used antipersonnel mines since the 1991 Gulf War, hasn't exported mines since 1992 and hasn't produced them since 1997, Steve Goose, director of the Arms Division of Human Rights Watch, told a briefing on Monday.
The review conference in Colombia on Sunday is expected to draw more than 1,000 people representing more than 100 countries, including dozens of ministers and several heads of state.
It will look at the progress and way forward for a broadly popular treaty that has helped cut landmine casualties around the world and provide relief to victims.
Kelly said the United States would send an interagency delegation of humanitarian mine relief experts from the State Department, Defense Department, U.S. Agency for International Development and the Centers for Disease Control and Prevention to observe the conference.
"As a global provider of security, we have an interest in the discussions there," Kelly said. "But we will be there as an observer, obviously, because we haven't signed the convention, nor do we plan to sign the convention."
U.S. SENDING OBSERVERS
It is the first time the United States has sent a team of observers to a gathering of states that have accepted the treaty, a move that was welcomed by anti-landmine campaigners.
"The very fact that they are showing up we take as a positive sign of movement on this issue within the Obama administration," Goose said.
"We hope they're not coming empty-handed," he added. "We very much want them to come and say that they intend to join this convention. Even if they can't give a timeline, we want them to say they intend to join at some point in time."
Anti-mine campaigners said a declaration of intent was particularly important because the Bush administration reversed U.S. policy on accepting the convention and said it would never join.
While Kelly's comment indicated no shift in administration policy, Jeff Abramson, deputy director of the nonpartisan Arms Control Association, said the United States was expected to make a statement at the conference that might shed more light on the decision.
He said it would be "disappointing" if a U.S. statement at the Cartagena summit closed off the potential for launching or continuing a review of U.S. policy on landmines.
Kelly said the United States was "the world's single largest financial supporter of humanitarian mine action," having provided more than $1.5 billion since 1993 to support mine clearance and destruction of conventional weapons.
In contravention of the treaty, however, the United States stockpiles some 10 million antipersonnel mines and retains the option to use them.
But use of the mines would pose big problems for Washington, Goose said, because most of its allies -- including all but one NATO country -- are parties to the treaty and are pledged not to help other countries use the weapons.
(Editing by Sandra Maler) ((email@example.com; 202 354 5866; firstname.lastname@example.org))