Russia appeared to rule out full Iranian membership of a Central Asian regional security bloc on Friday over U.N. sanctions Russia voted for.

Iran has observer status within the SCO.

Two days after backing sanctions against Iran in the U.N. Security Council, "If the Security Council has imposed sanctions, such a country cannot become a full member," Russian Foreign Minister Sergei Lavrov told reporters, making no specific reference to Iran.

Iran's president, Mahmoud Ahmadinejad, has upstaged previous events. In a snub to the West at last year's meeting, Shanghai Cooperation Organisation leaders congratulated him on a disputed election victory.

Ahmadinejad did not travel to this year's meeting in the Uzbek capital Tashkent. Lavrov said the Iranian leader had been invited but declined to attend.

Members of the SCO, led by Russia and China, approved new rules on membership of the body, which focuses on security issues in Central Asia. Kazakhstan, Kyrgyzstan, Uzbekistan and Tajikistan are also full members. As well as barring countries under U.N. sanctions, the document, seen by Reuters, limits membership to countries within the Eurasian continent who have diplomatic relations with other members and are either SCO observers or dialogue partners.

Pakistan, India and Mongolia -- as well as Iran -- are observers. Belarus and Sri Lanka are dialogue partners.

Iran was represented by its foreign minister, Manouchehr Mottaki, who described the latest U.N. sanctions as "unfair and devoid of legal grounds". In a speech to the summit he said Iran was "above political games".

The Security Council approved a fourth round of sanctions against Iran on Wednesday.

UN vote came despite Turkey-Brazil efforts that yielded a nuclear swap deal with Iran.

Turkey and Brazil voted against it while Lebanon abstained. However, there were 12 votes in favor of the resolution.

Ahmadinejad on Tuesday warned the Kremlin against siding with "Iran's enemies" in supporting sanctions.

Agencies