United Nations, APRIL 13, SPA -- U.N. Secretary-General Ban Ki-moon said Thursday he had spoken to Lebanese Prime Minister Fouad Siniora regarding the establishment of an international tribunal to try suspects in the assassination of former Lebanese Prime Minister Rafiq Hariri, but he noted that the process was in the hands of the Lebanese. I am very much concerned by the lack of progress in this issue. The United Nations has taken all steps , by signing this document allowing a tribunal to be created . Again, I hope the Lebanese government will take the necessary constitutional procedures, Ban told reporters. This is very important and urgent, but at the same time a sensitive issue , Ban said, adding that Siniora was frustrated with the process. Late last month, Ban received a letter from several Lebanese parliamentarians asking the United Nations for help on establishing the tribunal. . Under Lebanese law, a session of parliament must be called in order for the body to approve the creation of an international tribunal to try Hariri s killers. Ban will travel to Damascus next week to speak with Syrian officials, including President Bashir Al-Assad, to discuss a number of regional issues.--SPA www.spa.gov.sa/440624