BRUSSELS (Reuters) - The chairman of European Union leaders, Donald Tusk, said the bloc is ready to start negotiating a transition period with Britain after it leaves the EU, and it wanted more clarity from London on how it sees their new relationship after leaving.  Tusk said Britain will have to respect all EU laws during the transition, as well as respect its budgetary commitments and the bloc s judicial oversight. But it would no longer take part in decision-making that will be done by the 27 remaining states.  We are ready to start preparing a close UK-EU partnership in trade but also fight against terrorism and international crime, as well as security, defense and foreign policy,  Tusk told reporters after British PM Theresa May arrived in Brussels with a Brexit deal. Tusk said, however, too much time was spent on negotiating the outlines of Britain s exit, which he said was the relatively easier part.   We all know that breaking up is hard but breaking up and building a new relation is much harder,  he said.  So much time has been devoted to the easier task and now ... we have de facto less than a year,  left of talks before Britain is due to leave in March, 2019.  