Sharply criticising the North Korean nuclear tests, United Nations Secretary General-designate Ban Ki Moon has asked the world community to send out a "very strong, unified and clear" message to Pyongyang so that it would not have "any temptation to engage in further negative activities".The strong remarks from Ban came at the first press conference he held within two hours of his election to the top United Nations post by the General Assembly for five years with acclamation and without vote amidst cheers yesterday.Observing that there are daunting challenges to peace, development and human rights, he said the Iranian nuclear issue, humanitarian crisis in Darfur, the Middle East and conflicts in Africa call for a concerted approach.He expressed confidence that the Council would make North Korea aware of the "determined will of the international community" against it possessing or experimenting with nuclear weapons.Addressing the General Assembly and later talking to reporters, he pledged to work "diligently" to protect the most vulnerable members of the humanity and for peaceful resolution of threats to international peace and security.(PTI)