Russian President Vladimir Putin, left, who arrived to attend the Gas Exporting Countries Forum, meeting with Iranian Supreme Leader Ayatollah Ali Khamenei in Tehran, Iran, on Monday. REUTERS/Alexei Druzhinin/Sputnik/Kremlin Russian President Vladimir Putin has eased an export ban on nuclear equipment and technology to Iran, a Kremlin decree published on Monday showed, according to Reuters.

Russia was one of the six world powers that signed a landmark agreement with Iran this past July aimed at curbing Iran's nuclear program in exchange for sanctions relief.

The Russian decree, issued on the same day as Putin arrived in Iran on an official visit, said Russian firms were now authorized to export hardware and to provide financial and technical advice to assist Iran in three specific areas of the country's infrastructure.

The decree allows Russia to help modify two cascades at Iran's Fordow uranium enrichment plant, to support Iranian efforts to export enriched uranium in exchange for raw uranium supplies, and to help Iran modernize its Arak heavy-water reactor.

Under the nuclear agreement, Iran will modify the uranium enrichment cascades in Fordow, a once secret facility built inside a mountain on an Iranian Revolutionary Guard Corps base, to instead enrich non-fissile materials. Iran must also reduce its supply of low-enriched uranium, which stood at 7,845 kilograms in August, to 300 kilograms. And Iran has to modify its heavy-water reactor at Arak so it will be unable to produce plutonium for a nuclear weapon.

The Russian decree paves the way for Moscow to assist Iran in meeting these requirements under the deal, which will lift international sanctions on Iran in exchange for at least a decade of curbs on the country's nuclear activity. The nuclear deal actually commits its signatories to assisting Iran in modifying parts of its nuclear infrastructure, and in helping Tehran build other aspects of its program, such as its fuel-fabrication capability.

At the same time, the export of Russian technology and expertise could mean a closer economic and strategic relationship between the two countries, which have numerous shared interests throughout the Middle East.

An S-300 missile system. AP On November 9, Russia and Iran signed a contract finalizing the sale of S-300 missile to Tehran. The advanced anti-aircraft system, which can strike targets at a distance of up to 93 miles flying as high as 88,000 feet and would greatly complicate any aerial attack on Iran's nuclear infrastructure, will most likely be delivered to Iran by the end of 2016, according to the Financial Times. Iran and Russia both support the regime of Syrian president Bashar Assad, and each country has deployed its military in an attempt to prop Assad's government.

The visit is itself a sign of the countries moving closer together now that the nuclear deal has been signed: This is Putin's first visit to Tehran since 2007.

Putin, who will attend a summit of gas-exporting countries on Monday in Tehran, is also expected to meet Iranian President Hassan Rouhani and discuss the Syria conflict.