NEW DELHI — Russian President Vladimir Putin pledged Thursday to supply India with oil, weapons and nuclear power reactors, buttressing a long-time friendship with Asia’s third-biggest economy as ties deteriorate with the West over Ukraine.

Prime Minister Narendra Modi reassured Putin, who is on a visit to the Indian capital, that India opposes sanctions against Russia. He also said Russia remains India’s most important defense partner and welcomed Putin’s offer to make an advanced helicopter in the country.

“The character of global politics and international relations is changing,” Modi told reporters in New Delhi in a joint briefing with Putin. “However, the importance of this relationship and its unique place in India’s foreign policy will not change.”

Putin is seeking new markets for its oil and natural gas as the nation’s faltering relations with the United States and Europe amid the Ukraine conflict prods it toward a recession. Russia’s ruble extended its worst rout in 16 years Thursday even after the Bank of Russia raised its key rate for the fifth time this year.

Russia holds the world’s second-biggest natural gas reserves and is among the globe’s biggest oil producers. Among the agreements Thursday was a 10-year deal that will raise Indian imports of Russian oil almost 40-fold from current levels.

The two nations plan to study the possibility of a hydrocarbon pipeline system connecting India and Russia, according to a joint statement.

The two nations also agreed to identify a new site for Russian reactors and to jointly construct nuclear power plants in other countries.