MOSCOW (AP) -- Russia could expand arms sales to Iran and revise the terms of U.S. military transit to Afghanistan if Washington launches a strike on Syria, a senior Russian lawmaker said Wednesday.

Alexei Pushkov, the Kremlin-connected chief of the foreign affairs committee in the lower house of parliament, told lawmakers that Moscow hopes that the U.S. will back Russia's proposal for Syria to put its chemical weapons under international control for their subsequent dismantling.

During Wednesday's debate in the Russian parliament of a draft resolution on Syria, Communists called for an increase in Russian weapons supplies to Iran and a revision of conditions for transit via Russia of supplies for U.S. forces in Afghanistan.

Pushkov said such action now would be premature as Russia and the U.S. are working to find a diplomatic solution to the crisis, but he warned that if the "party of war" prevails in Washington, Russia should consider those moves.

"If the U.S. takes the path of exacerbating the situation and forgoing diplomacy for the sake of a military scenario, such measures would seem absolutely justified to me," Pushkov said.

President Vladimir Putin is set to meet with Iran's President Hasan Rouhani in Kyrgyzstan on the sidelines of a security summit later this week.

The business daily Kommersant -- which has strong Kremlin connections -- reported Wednesday that the Kremlin has decided to sign a new deal for the delivery of air defense missile systems to Iran. It cited "a source close to the Kremlin."

The deal would replace a 2007 contract that Russia scrapped in 2010 under U.S. and Israeli pressure.

The initial contract called for the delivery of the S-300 PMU missile systems, while the new deal would envisage the delivery of a different weapon, the S-300 VM, also known as Antey 2500.  That missile system has a shorter range and lower velocity, but it's still a very potent weapon capable of engaging enemy aircraft and cruise missiles with deadly efficiency.

Kommersant quoted a Russian military expert, Vladimir Yevseyev, as saying that the air defense system allegedly being offered by Russia may suit Iranian needs even better than the initial offering.

There was no official comment to the report from Russian officials, who typically refuse to discuss weapons deals in the making.

Iran, which has filed a lawsuit against Russia in international arbitration for reneging on the 2007 contract, has signaled an interest in the Russian offer, which was first reported by Kommersant over the summer.

Kommersant said that Russia may also sign a contract for building a second reactor at Iran's first nuclear power plant in the southern port of Bushehr.