Russia closed a defence deal with India on Monday that will step up arms sales to New Delhi, in a move to reinforce the countries’ military cooperation.

Prime Minister Manmohan Singh and visiting Russian President Vladimir Putin concluded talks with a billion dollar weapons deal, including the supply of 71 military helicopters for $1.3 billion and licensed production to assemble 42 Sukhoi fighter jets worth $1.6 billion.

Both countries have also agreed to cooperate on combating extremism and drug trafficking in Afghanistan following the withdrawal of international combat troops in 2014.

“I would like to stress that the deepening of friendship and cooperation with India is among the top priorities of our foreign policy,” Putin said in an article he wrote for Indian daily newspaper The Hindu.

“The strategic nature of partnership between India and Russia is witnessed by the unprecedented level of our military and technical cooperation,” adding that “the joint development of advanced armaments rather than just purchasing military products” is the key to future relations.

The two leaders also held wide-ranging discussions during the one-day visit and have moved forward with several agreements such as civil nuclear cooperation, bolstering economic ties and closer cultural and tourism exchanges.