LONDON — With a deadline for an Iranian nuclear deal fast approaching, Secretary of State John Kerry embarked Wednesday on a frenzy of high-stakes diplomacy aimed at securing an agreement — or at least preventing the process from collapsing.
As senior negotiators huddled for a second day in Vienna, Kerry held separate meetings in London, before heading to Paris. Kerry was still considering when he might join the larger effort in the Austrian capital, where negotiators are scrambling to forge a pact over the next five days to prevent Iran from reaching the capability to produce atomic weapons.
Despite his efforts, though, signs pointed to Monday’s deadline passing without a deal and the negotiations being extended a second time.
In London, Kerry met Wednesday at his hotel with Foreign Minister Yusuf bin Alawi of Oman, a key bridge between Washington and Tehran, a senior US official said. Bin Alawi was in Tehran last weekend and met with Kerry on Tuesday. Their follow-up meeting was unannounced.
Oman is not party to the talks among Iran, the United States, Britain, China, France, Russia, the European Union, and Germany.
But it is unique among the Gulf Arab states for its close ties with Iran, holding high-level nuclear talks this month and serving as the site of secret US-Iranian gatherings dating back to 2012. Those discussions laid the groundwork for an interim agreement reached a year ago, which the negotiating countries hope to cement with a comprehensive accord in Vienna.
Details of Kerry’s meetings with bin Alawi were not immediately clear.
In Washington, President Obama’s nominee to be Kerry’s deputy at the State Department said he believed it would be difficult to meet the deadline.
‘‘It’s not impossible,’’ said Tony Blinken, currently Obama’s deputy national security adviser. ‘‘It depends entirely on whether Iran is willing to take steps it must take to convince us, to convince our partners, that its program would be for entirely peaceful purposes. As we speak, we’re not there.’’
In Paris, Kerry will meet Saudi Foreign Minister Saud al-Faisal and French Foreign Minister Laurent Fabius. Those meetings are key because French objections last year delayed the adoption of an interim agreement by several weeks, and Saudi Arabia remains deeply concerned about the potential for its arch-rival Iran to win concessions from the West.
The Obama administration also is trying to satisfy concerns in Congress, where many now see an extension of talks as preferable to an agreement that doesn’t do enough to cut off Iran’s path to a nuclear bomb.
Republicans in particular want more time so that they can attempt to pass sanctions legislation that would pressure Iran into greater concessions.