New U.S. Secretary of State John Kerry and his South Korean counterpart Kim Sung-hwan talked over the phone Sunday in which they agreed that North Korea will face "significant consequences" in case of continued provocations.

Kerry and Kim agreed on the need to "ensure that North Korea understands that it will face significant consequences from the international community if it continues its provocative behavior," according to Kerry's department.

The joint warning came amid reports that Pyongyang's nuclear test appears to be imminent.

"In addition to discussing the DPRK (North Korea), the secretary and Kim reviewed other issues in our bilateral relationship and underscored the importance of continued close collaboration when the Park administration takes office," it said in a press release without elaborating.

Kerry, who was sworn in as Washington's top diplomat on Friday, also had phone talks with Israeli Prime Minister Benjamin Netanyahu, Palestinian Authority President Mahmoud Abbas and Japanese Foreign Minister Fumio Kishida.

Kerry is scheduled to speak briefly to the media on Monday morning when he enters the State Department building. (Yonhap News)