Russia is dismissing as "rumors" reports it hosted an Iranian general, despite a United Nations travel ban on such a visit.
Russian Foreign Minister Sergei Lavrov said "all commentaries" on these rumors have been made and there is nothing he can add to what he called a “chain of suspicions” from his American colleagues.
The U.S. State Department said last week a July visit to Russia by Iranian Major General Qasem Soleimani had violated the U.N. ban. The general is a commander in Iran's Revolutionary Guard and has been on the U.N. blacklist for travel since 2007.
The United States accuses Soleimani of responsibility in the deaths of 500 troops in Iraq and a failed attempt to assassinate the Saudi Arabian ambassador in Washington.
A Russian deputy foreign minister on Friday rejected the State Department statement, saying Moscow earlier informed the United States it had no information of any visit.
The U.N. sanctions against Iranian officials are for their links to Tehran's nuclear and missile programs.
Lavrov met earlier Monday with his Iranian counterpart, Mohammad Javad Zarif, in Moscow to discuss increasing cooperation after the Iran nuclear deal.
Zarif said the agreement, which Russia helped negotiate, would boost bilateral ties. Relations between the two countries have been good, he added, and the deal will have a positive impact on developing relations in all areas, including the economy and defense.
The deal, signed last month in Vienna, lifts sanctions against Iran in return for limits on its nuclear program.
Tehran said it only wants peaceful nuclear energy, but the West suspects it was developing a nuclear weapon.
Russia is eager to see the sanctions lifted so it can do business with Iran on nuclear power, oil and gas, and military hardware.
The Russian and Iranian foreign ministers also voiced support for besieged Syrian President Bashar al-Assad.
They repeated Moscow and Tehran's long-standing position that Assad's resignation should not be a precondition for a peace deal.
Russia and Iran are the Syrian leader's main backers, but Moscow has been positioning itself as a peacemaker.
Lavrov last week hosted separate talks with the main Syrian opposition, the Syrian National Coalition, as well as his Saudi Arabian counterpart, who say Assad lost his legitimacy and should be removed.
After the talks, the Syrian National Coalition said Moscow was not committed to keeping Assad in power, but was focusing on Syria's territorial integrity.
Russia is pushing the West for a coalition to fight the Islamic State terrorist group, but the United States and Saudi Arabia have resisted including Syrian and Iranian forces in the partnership.
US missile defense
Russia also wants the United States to scrap a missile defense system it plans for Europe to protect against rogue states such as Iran.
Moscow said Iran is no longer a threat, and it has concerns the missiles could be used to contain Russia.
But critics point out the nuclear deal does not include limits on Iran's ballistic missile development.
Western and Russian officials acknowledge the U.S. missile defense system could not effectively counter Moscow's ballistic missile and nuclear arsenal.
Russia won rare praise from the West over its role in the Iran nuclear deal, despite tensions over Moscow's military intervention in Ukraine.
Lavrov also said Monday he suspects Ukrainian forces are preparing for an offensive after intense fighting in recent days with pro-Russia rebels.
Kyiv claims it is only returning fire and the clashes erupted when their troops repelled an attack by rebels equipped with Russian tanks.
Moscow continues to deny sending troops or weapons to support the rebels, despite mounting evidence.