"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 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 such a statement shut the door to continuing a review of U.S. policy.
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 using 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.