BRUSSELS (Reuters) - The European Union s Brexit negotiator praised on Friday the speech of British Prime Minister Theresa May for a  constructive spirit  in divorce talks with the EU, but said he needed more clarity on what some of her declarations meant.  The speech shows a willingness to move forward, as time is of the essence,  Michel Barnier said in a statement.  Prime Minister May s statements are a step forward but they must now be translated into a precise negotiating position of the UK government.  Barnier, who is conducting negotiations on Britain s exit form the EU in March 2019 on behalf of the 27 governments remaining in the bloc, noted May did not address the issue of the future of Northern Ireland s relations with Ireland. He also said he would need to discuss further May s pledge that Britain recognized that no EU country would have to pay more in to the EU budget or receive less from it because of Brexit.  We stand ready to discuss the concrete implications of this pledge. We shall assess, on the basis of the commitments taken by the 28 Member States, whether this assurance covers all commitments made by the United Kingdom as a Member State of the European Union,  he said. He said that Britain s request for a two-year transition period after it leaves the EU, during which London would still be part of the EU s single market, could be discussed as soon as there was agreement on the principles of the divorce. 