A commmitment to refrain from introducing new measures that are not consistent with an agreement. In the Uruguay Round, the agreement not to introduce new GATT-inconsistent trade-restricting and trade-distorting measures during the negotiations. See rollback.
a commitment not to increase any trade barriers --- Such commitments are usually offered at the start of multilateral trade negotiations as an indication of good faith.
a situation in which no progress can be made or no advancement is possible; "reached an impasse on the negotiations"