WASHINGTON (AP) — For the United States and its negotiating partners, the next round of nuclear talks with Iran could present a difficult decision: to sign another temporary agreement or accept nothing less than an ambitious, multiyear accord to dismantle the Islamic republic’s nuclear program.

To critics in the Middle East and on Capitol Hill, anything short of a full agreement may be seen as merely allowing the Iranians to stall for time, potentially reaping billions of dollars in eased economic sanctions while still refining their nuclear technology. It could also make it harder for President Barack Obama to hold off a congressional push for tougher sanctions on Iran, which the White House has warned would upend the fragile diplomacy.