Complex sentence: When in power during the years 2004--14, the Congress party worked on ties with the United States, and Prime Minister Manmohan Singh visited the United States in July 2005, and initiated negotiations towards an Indo-US civilian nuclear agreement.
Split into simpler sentences: When in power during the years 2004--14, the Congress party worked towards stronger ties with the United States. Several delegates including Prime Minister Manmohan Singh visited the United States in July 2005, initiating negotiations over the Indo-US civilian nuclear agreement.