Russia and Iran, which have grown closer in recent years, have joined forces to avoid Western sanctions on their exports by building a new waterway-railway route from Russia-occupied territories in Ukraine to the Islamic Republic’s southernmost ports.

Russia and Iran, united by their increasingly close military ties and the fact that they are both pariahs in international trade due to Western sanctions, are now looking to expand their trade ties with Asia, according to Bloomberg.

They are expanding canals on navigable rivers and building railroads to support growing trade. It is estimated that the two countries will invest $20 billion in the route. The new transcontinental route would begin at the Sea of Azov, passing through Mariupol, a major Ukrainian port that Russia occupied after invading Ukraine earlier this year.

According to vessel tracking data compiled by Bloomberg, dozens of ships, both Russian and Iranian, are already traveling up and down the route, which is much shorter than the route entirely by sea from the Russian ports on the Baltic Sea via the Mediterranean and through the Suez Canal. Maria Shagina, an expert on sanctions and Russian foreign policy at the International Institute for Strategic Studies was quoted as saying, “This is about establishing sanctions–proof supply chains all the way through.”

Iran and Russia have recently strengthened their ties, signing a 20-year strategic agreement earlier this year. Aside from trade, the two countries have strengthened military ties, with Tehran regularly delivering weapons to Moscow, Russia transferring weapons to Iran, and a growing agenda of enhanced security cooperation.

Last month, reports surfaced that Russia and Iran had reached an agreement that would allow Russia to produce Iranian-designed drones for use on the Ukrainian battlefield. In recent months, Russia has used hundreds of Iranian-made suicide and combat drones against Ukrainian military and civilian infrastructure.