The United States and Russia said Dec. 4 they had agreed to maintain the provisions of a major nuclear arms treaty just hours before the pact expired after being in force for 18 years while negotiations continue on a new agreement.

In a joint statement by Russian President Dmitry Medvedev and U.S. President Barack Obama, the two sides pledged to coninue to work together "in the spirit" of the expiring 1991 Strategic Arms Reduction Treaty.

The pledge could be interpreted to mean that the two sides will continue to respect the expired START treaty's limits on nuclear arms and allow inspectors to continue verifying that both sides were living up to the deal.