The U.S. has four "foundational" agreements that it signs with its defence partners. The Pentagon describes the agreements as "routine instruments that the U.S. uses to promote military cooperation with partner-nations". American officials have stated that the agreements are not prerequisites for bilateral defence co-operation, but would make it simpler and more cost-effective to carry out activities such as refueling aircraft or ships in each other's countries and providing disaster relief. The first of the four agreements, the General Security Of Military Information Agreement (GSOMIA), was signed by India and the U.S. in 2002. The agreement enables the sharing of military intelligence between the two countries and requires each country to protect the others' classified information. The second agreement, the Logistics Exchange Memorandum of Agreement (LEMOA), was signed by the two countries on 29 August 2016. The LEMOA permits the military of either country to use the others' bases for re-supplying or carrying out repairs. The agreement does not make the provision of logistical support binding on either country, and requires individual clearance for each request. The third agreement, Communications Compatibility and Security Agreement (COMCASA) was signed during the inaugural 2+2 dialogue in September 2018. It is an India-specific variant of Communications and Information Security Memorandum of Agreement (CISMOA) that enables the two countries to share secure communication and exchange information on approved equipment during bilateral and multinational training exercises and operations. The fourth agreement, the Basic Exchange and Cooperation Agreement (BECA), signed in 2020, permits the exchange of unclassified and controlled unclassified geospatial products, topographical, nautical, and aeronautical data, products and services between India and the US National Geospatial-Intelligence Agency (NGA).