A senior U.S. diplomat is in Haiti trying to resolve a political impasse over long-stalled legislative elections.

Thomas Shannon is counselor to U.S. Secretary of State John Kerry. Shannon was meeting with Haitian Prime Minister Laurent Lamothe and members of Parliament in a brief visit to the Caribbean nation.

President Michel Martelly was supposed to call elections in 2011 for a majority of Senate seats, the entire Chamber of Deputies and local offices. But he hasn't done so because the Senate has yet to approve an electoral law authorizing the vote.

Some Senators say the proposed law is unconstitutional and improperly favors the Martelly government. They must approve it by January or Parliament will be dissolved.

Shannon declined to comment Thursday as he left a meeting in Parliament.