Arbitrator

Two companies A and B in an agreement agreed that A will appoint Arbitrator in case of dispute, which arose and A appointed Arbitrator. Arbitration is going on but B has expressed inability to pay fee to Arbitrator. 1. Can Arbitrator leave Arbitration on this ground. 2. Can Arbitrator force B to pay fee as it was agreed by it that A will appoint Arbitrator in case of dispute and not to pay fee of Arbitrator is violation of that Agreement.