Foreign Minister Yun Byung-se will depart for Washington late Sunday to sign a nuclear deal with the United States that would allow Seoul to expand its non-military nuclear activities, Yonhap news agency reported quoting the Foreign Ministry as saying.

Yun's trip to Washington until Tuesday comes as President Park Geun-hye postponed her planned trip to Washington last week citing the need for all-out efforts by her government to contain the Middle East Respiratory Syndrome virus that has claimed 14 lives in the country for the past weeks.

Park was to sign the nuclear deal that allows South Korea more leeway in uranium enrichment and research into reprocessing while in Washington.

U.S. President Barack Obama placed a phone call to Park on Friday to say he fully understood her decision to delay the planned visit, noting he has told his aides to consult with South Korean officials to quickly rearrange Park's trip.

Park was originally scheduled to hold summit talks with Obama on June 16.