Secretary of State John F. Kerry looks at traditional Omani daggers in the souk in Muscat, Oman, on Nov. 10. It was one of the few laid-back moments in two days of talks over Iran’s nuclear capabilities. (Nicholas Kamm/AP)

Secretary of State John F. Kerry completed two days of talks with Iran and the European Union on Monday, but there were no signs that they were any closer to a comprehensive deal that would limit Iran’s nuclear capacity.

Kerry left Oman late Monday after devoting more than 10 hours to talks over two days with Iran’s foreign minister, Mohammad ­Javad Zarif, and E.U. representative Catherine Ashton.

A senior State Department official, describing the tenor of the talks as “tough, direct and serious,” declined to characterize them as productive in any manner. The official said, however, that negotiators still believe it is possible to reach a comprehensive accord before the Nov. 24 deadline when an interim agreement expires.

The Reuters news agency ­reported an Iranian official as ­saying that little had been accomplished and that large gaps ­remained.

Just before the diplomats started an evening session, Kerry and Zarif gave terse assessments of the state of the talks in response to questions shouted out as the two men were being photographed.

Asked whether they were making progress, Zarif replied in English, “We will eventually.”

“We are working hard,” Kerry said when asked whether the talks would succeed, and then he repeated: “We are working hard.”

The United States and its allies — Britain, China, France, ­Germany and Russia — are pushing for relatively low caps on Iran’s nuclear capacity in order to complicate any attempts by ­Tehran to cheat and pursue a nuclear bomb. In return, they have offered to gradually lift economic sanctions that are strangling Iran’s economy amid falling oil prices. Iran has insisted that its nuclear program is solely for peaceful, civilian uses such as energy and medicine.

The talks, originally expected to last only one day, spilled over into a second day, reflecting the intense pressure on both the United States and Iran to settle some gaping differences by the deadline.

With time slipping away, no consensus has been reached on several fundamental matters. Among them are the number of centrifuges that Iran would be allowed to keep for enriching uranium, the time frame for lifting sanctions and the duration of a comprehensive nuclear accord, according to Western and Iranian sources familiar with the negotiations.

U.S. officials have been ­cautious about appearing overly optimistic, and President Obama said over the weekend that, ultimately, it may be impossible to reconcile the wide gaps.

Opposition in some quarters is fierce. In Israel, which considers Iran’s nuclear ambitions an ­existential threat, Prime Minister Benjamin Netanyahu said Monday that he had heard reports that a deal was imminent. He said he had sent letters urging the foreign ministers of all the countries negotiating with Iran — the five members of the U.N. Security Council plus Germany, a grouping known as the P5+1 — not to be too hasty in making a deal.

“This terrorist regime in Iran must not be allowed to become a nuclear threshold power,” Netanyahu said in a statement. “And I call on the P5+1 countries — don’t rush into a deal that would let Iran rush to the bomb.”

In one of the few laid-back moments over two days of earnest talks, Kerry took advantage of a break and dashed to the souk in old Muscat for some early Christmas shopping. He lingered over displays of frankincense, silver jewelry and ceremonial Omani daggers, and emerged carrying several white plastic bags.

Later Monday, Kerry left for Beijing, where he is to join Obama on the first leg of a trip designed to forge stronger U.S. economic and diplomatic ties to Asia. Negotiators from the United States and its allies in the nuclear talks will keep talking with Iran in Oman on Tuesday before a final push in Vienna starting Nov. 18.