FRANKFURT, Dec 18 - European Central Bank President Jean-Claude Trichet was quoted as saying on Thursday he was happy that both Europe and the United States were aiming to keep their currencies strong and stable. "I am rejoicing in that we are pursuing - not only on our side but on both sides of the Atlantic - long-term strategies that are aimed at delivering strong and stable currencies," Trichet told the Wall Street Journal Europe in an interview. "I noted that it had been recently confirmed by the U.S. authorities themselves," he added. The euro reached new record highs against the dollar above $1.24 on Wednesday, having already risen more than 18 percent against the greenback this year.//