DUBAI, Oct 18 (Reuters) - Iran backs talks with six major powers that are result-oriented, Iranian hardline President Ebrahim Raisi said on Monday, as Tehran and six powers struggled to overcome snags hampering the resumption of negotiations to revive a 2015 nuclear deal. "We are serious about result-oriented negotiations. ... If Americans are serious, they should remove unjust sanctions on Iran," Raisi told state TV. In April, Iran and six powers started talks to reinstate the deal that then-U.S. President Donald Trump ditched three years ago and reimposed sanctions that have squeezed Iran"s oil exports. But the talks were put on hold after Raisi"s election in June. Western powers have urged Iran to return to negotiations, warning that time is running out as Tehran"s nuclear programme is advancing well beyond limits of the nuclear pact. In response to Trump"s reimposition of sanctions, Tehran has breached the deal by rebuilding stockpiles of enriched uranium, refining it to higher fissile purity and installing advanced centrifuges to speed up output.