Congress and the Administration have fought bitterly over whether the 1972 treaty can be interpreted broadly enough to permit such tests.

Mr. Levin has said the negotiating record does not support the Administration's view that the treaty can be interpreted broadly.

First, treaties would be interpreted in the way Indians would have understood them and "as justice and reason demand."

This senior official said that there is nothing in the joint statement that contradicts the Administration's view that the treaty should be broadly interpreted.

But they also say the treaties have been interpreted to contain a reserve right for the Indians to hunt and fish on the reservations.

The Reagan Administration, by contrast, has argued that the treaty should be broadly interpreted.

The Russians have said that the treaty should be observed for at least 10 years and interpreted strictly.

Washington has argued that the treaty can be interpreted to allow the development of space-based systems.

Today, the Administration defended its position that the treaty should be more broadly interpreted.

The treaty has been variously interpreted by Lithuanian and Polish historians.