Goldman Sachs (GS - Get Report) CEO Lloyd Blankfein warned Friday that London's status as an international finance hub is at risk as a result of the country's decision to leave the European Union.

In an interview broadcast on the BBC, Blankfein said he was confident that London would remain the principal base for his bank's non-US operations, but nonetheless warned that there were things "beyond our control" that could alter those plans. He also warned that London's financial sector expansion, a key component of U.K. economic growth, could "stall" as a result of the ongoing Brexit uncertainty.

"I don't think it will totally reverse," he told the BBC. "It will stall, it might backtrack a bit, it just depends on a lot of things about which we are uncertain and I know there isn't certainty at the moment."

When asked if the bank, which has more than 6,500 staff working in various London offices, would consider relocating as a result, Blankfein sounded open-minded.

"A lot of people elect to have their European business concentrated in one place and the easiest place would be the UK," Blankfein said. "If you cannot benefit from access to the EU from the U.K., and no one knows what those rules and determinations will be, then the risk is that they'll be some adjustment that will cause some people to have a smaller footprint in the U.K."

"It is our hope that we will be able to conduct our business as close as we can to the way we conduct it today," he added. "But, without knowing how things will turn out, we have to plan for a number of contingencies.

Blankfein noted that Goldman Sachs has a "presence" in Dublin, Frankfurt and Paris, but indicated a preference for London as the bank's European HQ. However, he hinted that he was ready to shift staff to other locations if U.K. negotiators aren't able to clarify how and if investment firms will be impacted by Brexit. 

"If there's no period of time to implement whatever changes are brought about form the negotiations, we may have to do things prematurely and will have to do a range of things as a precaution, although right now we're trying to avoid that," Blankfein said.