India will continue to explore payment options for oil imports from Tehran and will only abide by U.N. sanctions and not those imposed by any bloc of countries, a government official said. \"As of now, supplies are on and Iran has been very positive and we are still optimistic,\" Indian Oil Minister S Jaipal Reddy said Wednesday. \"We will continue to explore various options of payment to Iran,\" he said, without disclosing what those options might be. Regarding a multidisciplinary Indian ministerial task force that visited Tehran last week to discuss options for payment for the $12 billion of crude oil India annually imports from Iran, Reddy said: \"We cannot disclose such things. We are determined to utilize the option of Iran and Iran has shown lot of understanding and goodwill.\" His remarks come as the European Union agreed Monday to ban Iranian oil imports beginning and to freeze the assets of Iran\'s central bank, increasing pressure on Iran to halt suspected nuclear weapons ambitions. \"We will scrupulously adhere to the sanctions imposed by the U.N. No less, no more,\" Reddy said. India is second-largest importer of Iranian crude oil after China. The Hindu newspaper, reporting that India\'s Essar Oil is believed to have renewed its contract for a supply of crude from Iran for another five years, quoted a company spokesman as saying that Essar \"continues to be able to source the crude that it requires from Iran.\" But Sudhir Vasudeva, chairman of state-run Mangalore Refinery and Petrochemicals Ltd., the largest buyer of Iranian oil, said the company was looking at diversifying its oil purchases. \"The crude oil import from Iran is an area of concern,\" he said. \"We are keeping all the options open. We have to be alive to the situation.\" While not providing figures, Indian Ambassador to the United States Nirupama Rao said India\'s purchase of oil from Iran had dropped slightly in last two years and that further declines were likely. \"Given the sanctions and given the difficulties in operating banking channels vis-a-vis Iran, obviously the volume can\'t be expected to go up in such a situation,\" the ambassador said. China also criticized the European Union for banning oil imports from Iran. \"To blindly pressure and impose sanctions on Iran are not constructive approaches,\" China\'s Foreign Ministry said in a statement Thursday, adding that China hopes to solve such disputes through dialogue and consultation, state-run news agency Xinhua reported. China\'s imports of crude from Iran rose more than 30 percent last year to 27.8 million metric tons, almost 560,000 barrels a day, customs data indicate.