The United States and European powers have resumed discussions on how to interact with Iran over its nuclear program, according to the Financial Times.

Iran has enriched uranium to such levels that US officials have warned in recent months Tehran could produce enough fissile material for a nuclear weapon in less than two weeks.

“There is recognition that we need an active diplomatic plan to tackle Iran’s nuclear program, rather than allowing it to drift,” a western diplomat told the Financial Times.

The US, France, Germany and the UK halted diplomatic efforts to resolve the crisis last September after Tehran angered rejected a draft proposal by the European Union to revive the 2015 nuclear agreement.

According to the Financial Times, there have been contacts with Iranian officials in recent months, including a meeting between officials from the so-called E3 - France, Germany, and the UK - and Ali Bagheri Kani, Iran's nuclear negotiator.

Diplomats and analysts say Rob Malley, the US Iran envoy, has met several times with Iran’s UN ambassador in New York Amir Saeid Iravani.

A person close to the administration said the talks focused mainly on the possibility of an exchange of prisoners with Iran, which holds at least three US citizens.

Last week, Tehran agreed to exchange prisoners with Belgium and released two Austrians.

IAEA detected particles enriched to almost weapons grade at the Fordow nuclear plant in January, indicating Iran enriched at least some uranium to 84% purity.