U.S. Secretary of State John Kerry is warning that public discussion of select details of the ongoing nuclear negotiations with Iran will make it more difficult to reach a deal that prevents the country from developing atomic weapons.

In comments to reporters in Geneva on Monday, Kerry said he was concerned by reports that details of the talks would be revealed in coming days. He did not elaborate, but Israeli Prime Minister Benjamin Netanyahu (neh-ten-YAH'-hoo) will speak in opposition to a potential Iran deal in an address to Congress on Tuesday. Israeli officials say Netanyahu plans to discuss elements of the negotiations that he finds problematic and dangerous to Israel.

Kerry will meet later Monday in Montreux with Iranian Foreign Minister Mohammed Javad Zarif for a new round of nuclear negotiations.