Vienna — As Iran final deal talks enter the one-month endgame, Iran and US negotiators staked out tough public positions and challenged the other side to make difficult decisions or risk seeing a historic opportunity elude them once again.

“We will not retreat from our [positions],” Iranian Foreign Minister Mohammad Javad Zarif said in a blustery press conference to Iranian journalists Friday (June 20), at the conclusion of five days of talks here. Negotiators from Iran and the six world powers (the five permanent members of the UN Security Council plus Germany, or P5+1) said they would return to Vienna for marathon nuclear talks beginning July 2 that are expected to last until the July 20 deadline when a six-month interim deal expires.

“We insist on our stances,” Zarif said. “With the resistance of the Iranian nation, we are in good condition. We want to reach a conclusion, [and] at the same time protect the rights of the Iranian nation.”

“It’s still unclear if Iran is ready to take all the steps necessary to ensure that Iran’s program is entirely peaceful,” the lead US negotiator, Undersecretary of State Wendy Sherman, told journalists here at the conclusion of the talks June 20. Iranian political leaders have repeatedly said “they don’t want or intend to develop a nuclear weapon. … It’s critical we give this process every chance to succeed.”