JERUSALEM (AP) — The long-delayed resumption of nuclear talks with Iran has gotten off to a rough start. Iran has been digging in and its negotiating partners are openly voicing frustration and pessimism. The U.S., European nations and even Iran’s ally Russia have raised questions about Iran’s seriousness. The talks aim to revive a 2015 deal that limited Iran’s nuclear program in exchange for relief from economic sanctions. Israel is not part of the talks but has a stake in their outcome. Israel’s prime minister, Naftali Bennett, on Sunday said Iran must “pay a price” for its nuclear activities.