Give short answers to the questions.

1.What is the current status of Iran’s nuclear program?

Iran’s ability to refine uranium, the fuel for peaceful nuclear energy and weapons, has grown significantly, according to the most recent inspection reports by the International Atomic Energy Agency,the nuclear-monitoring arm of the United Nations. Since last February, Iran has roughly quintupled, to more than 1,000, the advanced centrifuges at its main nuclear facility in the central city of Natanz. Iran also appears to have equipped a formerly secret subterranean facility known as Fordo, near the holy city of Qum, with 3,000 older-model centrifuges.

According to the most recent I.A.E.A. report, Iran has accumulated 185.8 kilograms, or about 410 pounds, of uranium enriched to about 20 percent purity, which is considered a short technical step away from refinement to bomb-grade material. Experts differ on the amount of 20 percent uranium Iran would need to make a bomb. But Israel, which has said it would regard a nuclear-armed Iran as an existential threat, has dropped numerous warnings that Iran should not exceed 240 kilograms, or 529 pounds.

Nonproliferation experts have also expressed concern over Iran’s construction of a thermal heavy-water research reactor in Arak, about 200 miles southwest of Tehran, because it could be a source of plutonium, another fuel for a weapon.

While Iran has promised more transparency in its nuclear program and repeatedly asserted its peaceful nature, the I.A.E.A. has expressed concern about unanswered questions over some aspects. The most prominent is Iran’s refusal to allow inspectors to visit Parchin, a highly restricted military site just south of Tehran suspected of having been the site of experiments, years ago, in testing triggers for nuclear weapons.

2.What was accomplished in the latest round of talks?

No breakthroughs were reported, but for the first time, Iran and the group of six major powers seeking to curtail the Iranian program – Britain, China, France, Germany, Russia and the United States – described the discussions as frank and detailed. The Iranians proposed what they called a compromise that would put unspecified limits on the program in exchange for an acknowledgment that the country has a legal right to enrich its own uranium. In addition, the Iranians want an early end to the economic sanctions imposed by Western nations, most notably constraints on Iran’s banking and oil industries. The major powers described Iran’s proposal as “an important contribution,” suggesting that they would respond with a counterproposal.

Aides to Hassan Rouhani, the country’s new president, have said Iran wants an agreement in six months.