Rome, April 24 - Enrico Letta, Italy's probable new premier, says that he will begin meetings on Thursday with various political leaders to try to forge a national government. Wednesday, his first day on the job, Letta was sounding optimistic despite the challenges ahead. "The first afternoon of work tells me of all the great difficulties, but I have also received so many messages of encouragement that my spirit is refreshed," he said. Letta said he must work quickly to begin the reforms assigned by President Giorgio Napolitano, who gave the new premier his mandate Wednesday morning. Napolitano wants Letta, 46, to be the premier of a government that has wide cross-party backing to end two months of political deadlock after February's inconclusive general election, with problems piling up for the recession-hit nation. That mandate includes a series of reforms to Italy's complex electoral laws. If Letta judges that he has sufficient support, he is likely to put forward a proposed new government for votes of confidence in the Upper and Lower House later this week, so it can then be sworn in.