"Over the past 1.5 years, the United States was quite passive in the region and allowed Moscow to take the lead on security issues in the area, including Karabakh," The Heritage Foundation's leading expert on Eurasia Ariel Cohen told Trend agency.

According to him, Russia recently signed a protocol renewing its lease on a military base in Gyumri, Armenia, which testifies to Moscow's growing influence in the region.

"This increases Russian involvement in protecting Armenia and shifting the balance in the region," he said, stressing the United States should boost its profile as a co-chair in the OSCE Minsk Group.

However, it is worth noting that the United States has little to offer for the negotiation process as a mediator, Cohen emphasized.