Iran said on Saturday the United States and world powers will be unable to restore stability in neighbouring Afghanistan without the help of the Islamic republic. "The US and global powers have realised that the issues in Afghanistan cannot be solved without the presence of the Islamic republic," Iranian government spokesman Gholam Hossein Elham told reporters. He was speaking a day after US Secretary of State Hillary Clinton said in Brussels that Iran would be invited to attend a high-level conference on Afghanistan at the end of the month. "There are a lot of reasons why Iran would be interested," she said. "So they will be invited. Obviously it is up to them to decide whether to come." Clinton's comments were seen as the latest overture by the US administration of President Barack Obama towards Iran. Elham said Tehran will consider the invitation. "If they need us they can offer, and we will consider the invitation based on an attitude of helping Afghanistan in any way," he said.