U.S. Secretary of State Antony Blinken and British Foreign Secretary Dominic Raab are expected to discuss issues related to Iran during their bilateral meeting on May 3 ahead of the start of a G7 ministers meeting in London.

The United Kingdom currently chairs the Group of Seven (G7) leading industrial countries and is involved in ongoing multilateral efforts to revive the 2015 nuclear agreement that curbed Iranian nuclear activities in exchange for sanctions relief.

The Blinken and Raab face-to-face meeting also comes amid disputed reports that prisoner swaps and the unfreezing of billions of dollars in assets might be under negotiation between the United States, Britain, and Iran.

Both Washington and London have acknowledged their ongoing efforts to seek the release of nationals held in Iran but avoided linking them to other topics, including mutually held nationals.

The British Foreign Office downplayed Iranian reports on May 2 that a deal had been reached to exchange disputed assets for the release of dual British-Iranian national Nazanin Zaghari-Ratcliffe, who has been held in Iran since 2016.

British officials on May 3 suggested the leaked reports were “disinformation” and sought to avoid linking a 400 million-pound ($550 million) historical debt to prerevolutionary Iran to Zaghari-Ratcliffe’s case.

But British Prime Minister Boris Johnson acknowledged, “We of course make sure that we do everything we can to look after the interests of Nazanin and all the very difficult dual-national cases we have in Tehran.”

The U.S. State Department on May 2 rejected as “not true” unsourced Iranian reports claiming a deal on a prisoner swap and $7 billion in frozen Iranian assets had been agreed.

Iran is known to be holding at least four Americans: father and son Baquer and Siamak Namazi, environmentalist Morad Tahbaz, and entrepreneur Emad Shargi.

The Iranian reports suggested Iranian nationals jailed in the United States might also be part of a deal.

The UN Security Council permanent members plus Germany wrapped up a third round of high-level talks on May 1 focused on bringing the United States and Iran back into full compliance with the Joint Comprehensive Plan of Action (JCPOA) that President Donald Trump pulled out of in 2018.

Prisoner swaps were a feature of the JCPOA nearly six years ago.

With reporting by AP and BBC