"There is no agreement in the offing, even as we continue to be willing to explore diplomatic paths," Blinken said at the Council on Foreign Relations in New York.

"We'll see by their actions," Blinken said of the future relationship, calling on Iran to choose to "not take actions that further escalate the tensions" with the United States and in the Middle East.

President Joe Biden took office with hopes of returning to a 2015 nuclear accord with Iran scrapped by his predecessor Donald Trump. But EU-mediated talks collapsed and mass protests in Iran made Washington increasingly hesitant to strike a deal with the clerical state.

Diplomats, however, say indirect talks have quietly resumed in recent months with Oman as an intermediary, with the focus largely on the status of US prisoners in Iran.

The talks on restoring the 2015 nuclear accord broke down over disputes on the extent of relief from sweeping US sanctions imposed by Trump and over when Iran would return to compliance by pulling back from countermeasures taken in response to the US withdrawal from the deal.

Blinken said the Biden administration had made a "good-faith effort" with European powers as well as rivals China and Russia to return and that for a time "that looked possible."

"Iran either couldn't or wouldn't do what was necessary to get back into compliance," he said.

Elsewhere in the region, Blinken has served as a go-between for Israel and Saudi Arabia -- which both have uneasy relations with the United States -- as they explore establishing relations.

"Both Saudi Arabia and Israel of course are interested in the prospect of normalization," said Blinken, who traveled to Saudi Arabia earlier in June.

"It is incredibly challenging, hard, not something that can happen overnight, but it's also a real prospect and one that we're working on," he said.

Israel in 2020 normalized relations with three Arab states -- the United Arab Emirates, Bahrain and Morocco -- in what both Trump and Prime Minister Benjamin Netanyahu see as a crowning achievement.

For Netanyahu, Saudi recognition would be an ultimate coup due to the country's size and influence in the Arab world and its status as the guardian of Islam's holiest sites. The Saudis have called for progress on the rights of the Palestinians.

Blinken on Tuesday spoke to Israeli Foreign Minister Eli Cohen to make a new call for de-escalation in the West Bank and to voice concern over recent unrest, which has included violence against Palestinian-Americans.

"We've told our friends and allies in Israel that if there's a fire burning in their backyard, it's going to be a lot tougher if not impossible to actually both deepen the existing agreements, as well as to expand them to include potentially Saudi Arabia," Blinken said.