Russia has allegedly established a new supply channel with Iran across the Caspian Sea, turning the route into a major part of military cooperation between Moscow and Tehran, The Telegraph reports.

The newspaper gives a central role to the Russian port of Olya in the northern Caspian. According to the report, Moscow receives drone components and ammunition from Iran through the port. The Telegraph argues that the Caspian Sea has effectively become a key supply corridor supporting the military efforts of both countries.

Washington currently has no means of stopping Russia from moving cargo to Iran along this route, the newspaper says. Its future, however, could depend on whether the United States develops a regional strategy built around Azerbaijan’s growing position in the South Caucasus.

The Telegraph says such an approach would also need to allow Ukraine to maintain military pressure on the supply corridor without creating the risk of direct US involvement.

Reports of possible military cooperation between Russia and Iran have surfaced before. In July, Reuters reported that US intelligence was examining Russia’s possible involvement in Iranian strikes on CIA facilities in the Middle East. A month earlier, Bloomberg said Tehran may have received Russian-made missiles.

In March, US media outlets also claimed that Moscow was allegedly providing Tehran with information on the location of American forces. CNN separately reported that Russia was allegedly advising Iran on tactics for using drones.

Russian Foreign Minister Sergey Lavrov has denied that Moscow provides Iran with intelligence information.