WASHINGTON (AP) — With an end-of-March deadline for a framework nuclear deal with Iran just days away, Secretary of State John Kerry is heading back to the negotiations.

Kerry was to leave Washington on Wednesday for what are expected to be make-or-break talks with Iran's foreign minister in Lausanne, Switzerland. He may be joined at the weekend by other foreign ministers from the five permanent members of the U.N. Security Council and Germany that are negotiating the deal.

The six nations and Iran have set a March 31 target to get the outline of an agreement that would put curbs on Iran's nuclear program in exchange for sanctions relief. They are aiming for a final deal by the end of June.

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