The return of Iranian oil to above-board markets — and the corresponding boost to tanker rates — is in jeopardy, according to the head of the International Atomic Energy Agency (IAEA).

Speaking at a press conference on Thursday, director general Rafael Mariano Grossi said the decision by Tehran to remove 27 IAEA monitoring cameras and other monitoring devices from nuclear facilities has set a four-week timer on talks to revive a 2015 nuclear deal.