Lebanese President Michel Aoun designated ambassador Mustapha Adib on Monday to form a new government after he secured the support of a majority of MPs.
The previous government quit on Aug. 10 in the wake of the catastrophic explosion at Beirut port.
Adib vowed Monday to swiftly launch a reformist government and seek international financial assistance after the Beirut blast deepened a political and economic crisis.
In a televised speech after his nomination, Adib said there is "a need to form a government in record time and to begin implementing reforms immediately, starting with an agreement with the International Monetary Fund".
An AFP correspondent then spotted him in an immaculate white shirt, tie and face mask touring the Gemmayzeh neighbourhood, which was hard hit by an August 4 Beirut explosion.
"I want your trust," the AFP correspondent heard him tell a resident.
The PM-designate also met with volunteers spearheading relief efforts in the blast-hit district, telling them he wanted the state to work with them in rebuilding Beirut.
No other senior government official has visited neighbourhoods near the port since the explosion.
Lebanon, mired in its worst economic crisis since the 1975-1990 civil war, started IMF talks in May but they have since hit a wall.
Three negotiators with the government's team have already quit in protest over the government's handling over the crisis.
An August 4 Beirut explosion that killed more than 180 people and laid to waste entire districts of the capital has compounded the country's economic woes.
It caused up to $4.6 billion worth of physical damage, according to a World Bank assessment. In addition, the report calculates the blow to economic activity at up to $3.5 billion.
In his speech, Adib said there "was no time for words, promises and wishes," pledging instead to enact swift reforms long demanded by the international community.
Adib has been Lebanon's ambassador to Germany since 2013 and his name only emerged on Sunday to replace Hassan Diab, whose government resigned in the aftermath of the deadly August 4 blast.
The 48-year-old was born in the northern city of Tripoli.