A proposed mechanism to release part of Iran’s frozen funds remains a key obstacle in the final stages of a potential agreement between Tehran and Washington, a source familiar with the matter told Al Arabiya on Thursday.

Axar.az informs according to the source, discussions are continuing over how part of the frozen Iranian funds would be handled, adding that the agreement is in its final stages.

The source also said that US President Donald Trump has informed mediators that he refuses to release any funds to Iran before the agreement is signed.

One proposal currently under discussion would see a special fund established to deposit the frozen Iranian assets, the source added.