Iran will further develop its nuclear program until the West changes its "illegal behavior," said Iran's top security official Ali Shamkhani in a meeting with the EU's top diplomat, Iranian state news agency IRNA reported.

"Iran's retaliatory actions in the nuclear sector are merely legal and rational responses to U.S. unilateralism and European inaction and will continue as long as the West's illegal practices are not changed," Shamkhani said.

Shamkhani did not detail what practices he was referring to.