UNITED NATIONS (Reuters) - U.N. Secretary-General Ban Ki-moon on Saturday expressed deep disappointment after troubled talks to end more than a year of bloodshed in South Sudan broke off without a deal a day earlier.

Friday's adjournment was the latest impasse in negotiations over the world's youngest country, where a political row between President Salva Kiir and his sacked deputy Riek Machar triggered a conflict that has killed more than 10,000 people.

"(Ban) expresses his profound disappointment following the unsuccessful conclusion of the (East African bloc) IGAD-led peace talks and the failure of President Salva Kiir and former Vice President Riek Machar to display statesmanship and reach an agreement on power-sharing," the U.N. press office said.

The U.N. statement said Ban "recalls" the Security Council's newly established sanctions regime, though it did not explicitly call for anyone to be sanctioned.

It added that Ban appealed for a resumption of the peace talks, noting that "he strongly urges both parties to refrain from any attempt to escalate the conflict."

U.S. State Department deputy spokeswoman Marie Harf on Friday issued a sharp rebuke to Kiir and Machar for not reaching an agreement.

"We strongly condemn the lack of political leadership to resolve this man-made conflict that has exacted a terrible cost over the past nearly 15 months," she said in a statement.

The 15-nation council on Tuesday established a sanctions regime for South Sudan but stopped short of imposing worldwide travel bans and asset freezes on officials in the conflict-torn country or an arms embargo.

The unanimously adopted resolution said the council would review the situation in South Sudan after the most recent round of talks and an April 1 deadline set by the regional East African IGAD bloc.

More than 1.5 million people have fled the ethnically fueled fighting which erupted in December 2013 and has often pitted Kiir's Dinka people against the Nuer of Machar.

(Reporting by Louis Charbonneau; Editing by James Dalgleish)