During a telephone conversation with Merkel, Mohammed Ghannouchi said the cooperation of the European Union was "indispensable" for the success of his country's transformation following last month's revolt.

"His government would soon issue invitations to a conference ... at which this process would be discussed in detail," Merkel's office said in a statement.

For her part, Merkel said that "the federal government (of Germany) would participate in a well-prepared conference to discuss ways of supporting Tunisia," according to the statement.

Ghannouchi told Merkel Tunisia was facing "big challenges", especially its fight against high levels of unemployment.

His government was engaged in a "wide-ranging democratisation" of the country, including free elections and economic reform, he added.

Mass protests sparked partly by poverty and unemployment erupted across the country last month, prompting strongman president Zine El Abidine Ben Ali to flee the country.