UNITED NATIONS, April 29 (UPI) -- Top U.N. political chief Lynn Pascoe' title='B. Lynn Pascoe' class='tpstyle'>B. Lynn Pascoe told the Security Council Baghdad expressed its gratitude to the world body but noted more work could be done.

Pascoe returned from a visit to Iraq to brief the Security Council, saying he was "absolutely convinced that the United Nations was doing its best" to guide Iraq through difficult times.

The challenges facing Iraqi national reconciliation and reconstruction, Pascoe said, extend beyond the borders of Iraq and require sustained international support to overcome.

The Iraqi government needs to tackle the fundamental issue of reaching a compromise power-sharing arrangement and set the path to determine the federal structure of Iraq in order to succeed. Pascoe praised Iraqi leaders for making progress on voter registration drives scheduled for June and provincial elections in October.

U.S. Ambassador to the United Nations Zalmay Khalilzad stressed that while progress in Iraq was uneven, the country made substantial improvements.