An intergovernmental Agreement on the construction of additional four units at Kudankulam NPP and cooperation at other sites was signed on December 5, 2008 during the official visit of Dmitry Medvedev, President of Russia, to India. The Intergovernmental Agreement was signed in New-Delhi by Sergey Kirienko, Head of Rosatom State Corporation, and Anil Kakodkar, Chairman of the Atomic Energy Commission of India.

The document was agreed by the parties in February 2008 on the eve of the visit to India of Victor Zubkov, Chaiman of the Government of the RF. The opportunity of signing it emerged after the Nuclear Suppliers Group lifted restrictions on the supply of nuclear materials and technologies to India in September 2008.

In March 2010 the Intergovernmental Agreement was signed between Russia and India on cooperation in the field of use of nuclear energy for peaceful purposes, as well as the "Road Map" of serial construction of the Russia-designed nuclear power plants in the Republic of India. The Memorandum of Understanding was also signed on expansion of cooperation in the construction of new power units on Kudankulam NPP site, and the Contract for performance of the priority design works for construction of 3-rd and 4-th Kudankulam NPP power units was concluded. Thus construction of at least 16 NPP power units based on the Russian design is assumed. Besides Kudankulam NPP first phase it is planned to construct as a minimum four power units more on the said site. It is planned to locate six new power units on Haripur NPP site. Construction of four power units more is planned on the third site.