WASHINGTON, Dec. 3 (Xinhua) -- U.S. Secretary of Defense James Mattis met with Indian Minister of Defense Nirmala Sitharaman here at Pentagon on Monday, highlighting security cooperation between Washington and New Delhi.

The United States and India have made meaningful progress advancing bilateral defense cooperation over the past year, Mattis said in a statement issued by Pentagon.

Mattis stressed the inaugural U.S.-India "2+2" Ministerial Dialogue, which was held in September in New Delhi, "made clear our commitment to further bolster our major defense partnership."

Sitharaman said that India saw the United States as an important partner in defense.

"We have good military-to-military cooperation, defense consultations, scientific and R&D work, defense trade, co-production and co-development, and industry collaboration," she said.

India, however, also traditionally enjoyed a close defense relationship with Russia.

In October, Indian and Russian leaders formally signed a purchase agreement for the S-400 air defense missile system worth more than 5 billion U.S. dollars.