New York, Dec 18 (DPA) UN Secretary General Ban Ki-moon said Friday the publication of leaked US diplomatic exchanges by whistle-blower website WikiLeaks is hurting diplomacy.

"It is unfortunate that these confidential documents have been leaked," Ban said at a news conference in New York. "The motivation on the part of the leakers will make it more difficult for the normal and reasonable conduct of the diplomatic business."

He called for a balance between the freedom of expression and the right to know with the preservation of confidentiality in diplomatic work.

Ban pointed out that legislation in some countries requires a 30-year hiatus before a secret document can be made public.

Among the cables WikiLeaks has been gradually publishing since Nov 28, is a dispatch from the State Department suggesting diplomats at the UN engage in espionage.

Ban said he had explained to US Secretary of State Hillary Rodham Clinton when WikiLeaks began making public some 250,000 leaked US diplomatic cables that his job as UN secretary general "is open and transparent."

"The conduct of diplomatic business has been transparent on the basis of mutual trust and confidentiality, and that I will continue the work the same way," Ban said.