Definition: Given a document, generate a short title of the document. The title should convey the main idea/event/topic about which the document is being written. Note that URLs in the text have been replaced with [Link].
Input: UNITED NATIONS (Reuters) - The United States will seek to boost its case for United Nations action against Iran when Security Council envoys visit Washington on Monday to view pieces of weapons that  U.S. Ambassador Nikki Haley  says Tehran gave to Yemen’s Houthi group.
 Haley  and  her  14 council colleagues will also lunch with President Donald Trump  the U.S. Mission to the United Nations said Friday.
 Haley  said last month  she  was exploring several U.N. options for pressuring Iran to “adjust their behavior”. But  she  is likely to struggle to convince some Security Council members  like veto powers Russia and China  that U.N. action is needed.
Diplomats  speaking on condition of anonymity  say  Haley  has not signaled which accountability option  she  might pursue or when.

U.S. seeks to boost case against Iran with U.N. Washington visit