"There is a proposal from the (EU) coordinator on the table and it will remain on the table.
They have accused Iran of going backwards in the talks, something Tehran denies.
"We hope that they will be honest and do not waste more time in order to pressure Iran."
Colonna said the United States and its European partners shared an identical position on the question of resolving an investigation.
A source close to Iran’s nuclear team said Tehran had lost interest in reviving a deal that can only last 2 years.