UN Secretary General Ban Ki-moon Wednesday heralded restoration of ties between the US and Cuba as "positive news", thanking leaders of both countries for "the very important step"."The news is very positive. I would like to thank President Barack Obama of the United States and President Raul Castro of Cuba for taking this very important step towards normalising relations," said Ban at a press conference here, Xinhua reported.Ban said that he welcomed Wednesday's development and hoped that the announcement will "help to expand further exchange" between the two peoples who have been separated for quite a long time."The United Nations stands ready to help both countries and to cultivate their good neighbouring relations," Ban said.Washington and Havana have not had full diplomatic relations since 1961. The US has imposed a sweeping economic and trade embargo on Cuba since 1962.