WASHINGTON – With nuclear talks stalled and a deadline approaching, a delegation of top U.S. officials will confer with Iranian counterparts at a hastily organized two-day meeting in Geneva next week, officials announced Saturday.

Deputy Secretary of State William J. Burns and White House foreign policy aide Jacob Sullivan are joining Under Secretary of State Wendy Sherman and her regular contingent of negotiating specialists to meet the Iranians on Monday and Tuesday in Switzerland, officials said.

The meetings come “at an important juncture of the negotiations, and they will give us a timely opportunity to exchange views,” a senior administration official said in a statement. “We believe we need to engage in as much active diplomacy as we can, to test whether we can reach a diplomatic solution with Iran on its nuclear program.”

The official, who declined to be identified, citing customary diplomatic ground rules, acknowledged that the sessions had not been long planned, though officials had anticipated there could be such bilateral sessions.

The meetings were described as “consultations” rather than “negotiations.”

Negotiators for six world powers and Iran have been pressing hard to complete by July 20 bargaining for a deal that will limit Iran’s nuclear program in exchange for a lifting of international economic sanctions.

But the two sides remained far apart at their last high-level meeting in Vienna in May, raising questions about whether they would be able to meet the July deadline – or seal a long-sought pact at all.

Some diplomats have said in recent days that there have been private discussions about extending the negotiating deadline, perhaps for a few months.

Later Saturday, the European Union said officials of other states, and not just the Americans, would be involved in what it described as a new round of “intensified” negotiations.

Helga Schmid, the EU’s political director, will take part in the U.S.-Iranian meeting, according to Michael Mann, a spokesman for EU foreign policy chief Catherine Ashton. Meetings between representatives from other states and the Iranians would follow, he said in a statement.

The six powers, the five permanent members of the United Nations Security Council plus Germany, had earlier scheduled a round of high-level talks in Vienna from June 16 to 20. The group, known as P5 Plus 1, comprises the United States, Russia, China, Britain, France and Germany.

Americans Burns and Sullivan were central players in secret bilateral diplomatic talks with Iran that helped open the way to the interim nuclear deal signed in November in Geneva.

Burns, a respected diplomatic veteran, and Sullivan, a trusted West Wing aide, were brought in partly to assure the Iranians of the White House’s political commitment to try to make a deal.

President Obama continues to signal that reaching a deal is a top security priority, although he has acknowledged that an agreement faces “long odds.”

The two sides appeared to reach an impasse in May when they had completed preliminary work and began trying to write the actual text of the agreement.

They remained divided on core issues, such as how much uranium-enrichment capacity Iran would retain. Each side blamed the other for failing to move quickly enough.

Iranian officials continue to declare publicly that they will not give up key elements of their $100 billion nuclear infrastructure. If Iran does not agree to give up most of its inventory of centrifuges, the deal could be blocked by U.S. lawmakers, many of whom are skeptical of the negotiations.

Iran maintains that it is not seeking nuclear weapons capability, although many countries dispute this and believe Iran is on the threshold of such a capability.

U.S. officials have been insisting that the earlier U.S.-Iranian talks – which annoyed other members of the six-party group – have ceased. Some analysts say they regret that this channel has been shut down, if it has, because Iran and the United States are the key players in the negotiations.

Bilateral sessions are a sensitive issue within the six-power group, because other players don’t want to feel left out of talks. The senior Obama administration official emphasized that the Geneva meetings would be held “within the context” of the six-party negotiation.

It has not been clear whether the negotiating impasse represents normal negotiating theatrics or something more dire.

If the talks collapse, the Western powers would presumably increase the sanctions pressure on Iran’s faltering economy. But Iran would also resume its nuclear development effort, taking it ever closer to a bomb-making capability.