French President Emmanuel Macron in high-stakes Lebanon reform drive

French President Emmanuel Macron pressed his "risky" drive for political change in Lebanon Tuesday, as the former French mandate marked its centenary while teetering on the brink of the abyss.

Macron has set an ambitious goal for his second visit since a deadly August 4 explosion ravaged Beirut: to press for change without being seen as a meddler.

He kicked off his trip on Monday, not by visiting political leaders, but by spending more than an hour with singing legend Fairuz, who at 85 is a rare unifying figure in Lebanon.

Macron ticked off more symbols to mark 100 years Tuesday since French mandate authorities proclaimed the creation of Greater Lebanon.

In the Jaj forest northeast of Beirut, he planted a cedar tree -- Lebanon's national symbol -- to express "confidence in the future of the country," his office said in a statement.

The French air force flew overhead leaving a trail of red, white and green smoke -- the colours of the country's flag.

Macron then returned for a second visit to Beirut port, ground zero of the colossal blast that killed more than 180 people, wounded at least 6,500 others and laid waste to entire districts of the capital.

He oversaw the distribution of aid from the the French helicopter carrier Tonnerre which arrived in Beirut on August 14.

Macron also met with some 400 French soldiers working with the Lebanese army to clear thousands of tonnes of debris from the port, vital for a country whose food is 85 percent imported.

Macron will then begin the most sensitive and anticipated leg of his visit: difficult discussions with under-fire political leaders widely blamed for the explosion, which was caused by a stockpile of ammonium nitrate fertiliser that had languished in the port for years.

Upon his arrival on Monday, Macron said his position towards Lebanon's political establishment "is unchanged: demanding without interfering".

For this position to be deemed credible by disenchanted Lebanese as well as by the rest of the international community, Macron must obtain swift results.

This is why on Monday evening he called for a so-called "mission government" to spearhead reforms just hours after Lebanese President Michel Aoun designated Mustapha Adib as the country's new prime minister.

The French president said it was not his place to "approve" of the designation of Adib -- a little known 48-year-old diplomat who since 2013 had served as Lebanon's ambassador to Germany.

But if Lebanon hopes to unlock desperately needed international assistance, political leaders must enact "real reforms" long demanded by donors, Macron said.

"If we do not do this, the Lebanese economy will collapse" and "the only victim will be the Lebanese people (...) who cannot go into exile", he warned on Friday.

Adib was named on Monday by political leaders widely seen as inept and corrupt by demonstrators who have taken to the streets in mass protests since October 17 against the entire political class.

The protest camp has already rejected the choice of Adib as premier, charging that he is too close to established political circles.

"No cabinet by or with the murderers" said posters brandished by demonstrators who waited for Macron outside Fairouz's home.

Late on Monday, Macron also met with former prime minister Saad Hariri at the Ottoman-era residence of the French ambassador, from whose porch 100 years ago Greater Lebanon was proclaimed.

After a lunch with Aoun in the presidential palace on Tuesday, he will meet with representatives of the country's top nine political blocs in the second such talks since the blast.

Representatives of the powerful Hezbollah movement, designated by the US as a terrorist group, will be among those meeting Macron.

The French president has justified his openness to "talk with everyone", including Hezbollah, by saying the Iran-backed group is "a political force that is represented in parliament".

With the protest camp warning against giving another lease of life to a hereditary ruling class that will only pay lip service to reform, Macron admitted in an interview that his brokering drive was a gamble.

"It's a risky bet I'm making, I am aware of it... I am putting the only thing I have on the table: my political capital," he told Politico.

Hezbollah chief Hassan Nasrallah said on Sunday his movement was "open" to a proposal made by Macron on his previous visit for a new political pact for the country.

Aoun and parliament speaker Nabih Berri have followed suit by backing calls for the formation of a "secular" state.