Under proposals discussed in rounds of talks in April, Iran would cap enrichment at 3.67%, in line with the JCPOA, all the sources said, including three Iranian officials. Tehran is also open to granting the IAEA expanded access to its nuclear sites, the Iranian sources said.

Israeli Prime Minister Benjamin Netanyahu has long been on a campaign against Iran's nuclear program and his opposition helped convince President Trump to withdraw from an Obama era deal meant to rein it in.