UN Secretary-General Kofi Annan on Wednesday voiced his concern about developments in Ukraine, where a tense situation has emerged due to disputes over the run-off Presidential election.

"While the United Nations is not in a position to comment on the conduct of the election, the Secretary-General believes a credible electoral process is critical to overcoming the current impasse," Annan's spokesman, Fred Eckhard, told reporters at the UN headquarters in New York.

The UN chief called on all sides to exercise maximum restraint and to adhere to democratic principles which are vital for the consolidation of democracy in Ukraine and the unity of the nation.

Source: Xinhua