Iran announced last week that it had successfully enriched uranium to 60% — its highest level yet. The country had not previously enriched uranium to higher than 20%, and 90% would be weapons-grade level. Government spokesperson Ali Rabiei told reporters on Tuesday that it had done this "demonstration of our technical ability," Reuters reported. He said Iran wanted to show that it could "respond to terrorist sabotage" after an attack on its Natanz nuclear plant earlier this month. Iran has blamed Israel for that attack, while Israel has not commented. Rabiei added that the country could reverse the enrichment process, and would do so if the US lifted sanctions.