Iranian President Mahmoud Ahmadinejad says his government does not oppose negotiating with Western powers about its nuclear program but also wants them to change what he calls their “foul” behavior toward Iran.

Speaking Thursday on a visit to the southern province of Kerman, Mr. Ahmadinejad accused the West of creating obstacles to negotiations. Iran and six world powers held their last round of nuclear talks one year ago and have been unable to agree on terms to renew them.

The European Union approved a phased ban on Iranian oil imports this week as part of a Western campaign to pressure Iran into stopping sensitive nuclear activities. The EU and the United States accuse Iran of trying to develop a nuclear weapon capability under cover of a civilian energy program, a charge Tehran denies.

In his latest remarks, Mr. Ahmadinejad downplayed the impact of EU sanctions on his government, saying they will hurt the EU rather than Iran.

The United States did not directly respond to the Iranian president's remarks, saying instead that Tehran should formally reply to a letter offering talks on specific nuclear issues sent by the European Union's foreign policy chief, Catherine Ashton. State Department spokesman Victoria Nuland said Ashton's letter provided the sole criteria for a resumption of dialogue.

The Reuters news agency says a respected U.S. research institute believes Iran is unlikely to rush into building a nuclear weapon because of a limited Iranian capacity to produce weapons-grade uranium.

In a draft report obtained by Reuters late Wednesday, the Institute for Science and International Security says it expects no Iranian decision on such a step until Iran develops an ability to make weapons-grade uranium “quickly and secretly.”

Reuters says the ISIS study was financed by a grant from the U.S. Institute of Peace, a non-partisan center funded by the U.S. government.

China's Foreign Ministry is criticizing the EU for banning Iranian oil imports. In a statement Thursday, Beijing said the move is not a “constructive” response to the nuclear dispute. Beijing is a key ally of Tehran and a top consumer of Iranian oil.

Iran has threatened to respond to Western sanctions by blocking the Strait of Hormuz, a crucial shipping lane for oil supplies to energy-hungry China and other nations. The United States has warned it will not tolerate such a move.