Silvio Berlusconi made a rare public appearance in Rome's halls of power on Tuesday as the ageing billionaire ex-premier sought to put his stamp on Italy's nascent government.

"We'll do our part, with loyalty and a constructive spirit," the 84-year-old Forza Italia leader said after leaving a meeting with Mario Draghi, the former European Central Bank chief seeking to form a new government of national unity.

Berlusconi, who was hospitalised last month with heart problems, appeared frail as he addressed reporters awaiting a glimpse of the man who dominated Italian public life for decades.

Berlusconi was hospitalised last month with heart problems
Berlusconi was hospitalised last month with heart problems AFP / Filippo MONTEFORTE

"The gravity of the hour requires everyone to put aside the calculations, tactics, the same electoral interests, to put the salvation of the country in first place," he said in brief comments.

Berlusconi, known as "Il Cavaliere" (The Knight), has been a central figure in Italian public life since the 1980s, as a flamboyant sports, media and business magnate and a three-time prime minister between 1994 and 2011.

But he has for months been holed up in southern France, where his daughter has a villa, after contracting coronavirus in September.

He spent a few days in hospital last month in Monaco after suffering heart problems.

Silvio Berlusconi meets with Mario Draghi in Rome
Silvio Berlusconi meets with Mario Draghi in Rome AFPTV / Andrea BERNARDI

Last week, he cancelled a planned trip to Rome to meet with Draghi on the advice of his doctor.

Draghi was called in by Italian President Sergio Mattarella to form a new government after the previous centre-left coalition led by Giuseppe Conte collapsed.

He so far has the support of almost all the main parties in parliament, but has yet to give details about his proposed cabinet or programme for government.

Italy is currently facing a punishing recession and a health crisis due to the coronavirus pandemic, which has left more than 91,000 people dead in the country.

In an interview with La Repubblica daily on Tuesday, Berlusconi said that "exceptional circumstances call for exceptional responses", explaining why he would support Draghi.

"About Draghi, I've never been wrong," Berlusconi told La Repubblica. "And I'm certain that I won't be wrong this time either."