India's widening trade deficit with Japan is a matter of concern for Indian exporters and there is a need for greater recognition of Indian certifications in Tokyo to improve market access, Ficci president Anant Goenka said on Tuesday. He added that there is a possibility of the two sides investing jointly in Africa to secure their supplies and expand mining capabilities. Indian companies, especially pharma, continue to face difficulties in accessing the Japanese market largely due to stringent certification and regulatory requirements, Goenka told reporters here. There is also "a fair amount of bias of buying products within Japan of Japanese companies," he added.