Russia and China stepped up their efforts on Friday to persuade Iran to accept a compromise proposal over its nuclear program that may avert the threat of U.N. sanctions against the Islamic Republic. Sergei Kiriyenko, head of the Russian atomic energy agency Rosatom, and Chinese Vice Foreign Minister Lu Guozeng arrived in Tehran for three days of talks over Iran’s nuclear impasse. Time is running out for Iran to avoid formal referral to the U.N. Security Council at a board meeting of the International Atomic Energy Agency (IAEA) in Vienna on March 6. Full Story