New Liberian President George Weah has appointed the first members of his cabinet, all of them men, largely naming party allies but picking a foreign minister close to former president Ellen Johnson Sirleaf.

The ex-international footballer Weah was sworn in on Monday at a stadium surrounded by ecstatic supporters, and filled some key ministerial posts later the same day.

In his inaugural speech, Weah vowed to crack down on entrenched corruption and encourage the private sector.

But the picks from his party come from outside the establishment and do not have significant government experience, potentially setting up a struggle with entrenched interests in the national congress.

The lack of women so far in the cabinet may also raise eyebrows after 12 years under Sirleaf, who pushed for women to enter public life and strengthened protections against abuse and female genital mutilation as her final act in office.

Weah's right-hand man is the chairperson of his Congress for Democratic Change (CDC) party, Nathaniel McGill, who becomes minister of state and chief of staff.

He guided the president through a bruising electoral campaign last year and was already his top aide.

Senior CDC figure Samuel Tweah becomes finance secretary, while Liberian lawyer Charles Gibson, a friend of Weah's, becomes Justice Minister.

Sam Mannah, the president's press aide from his years as a senator, becomes his press secretary.

Outgoing president Sirleaf has left her mark, however, with the appointment of former Unity Party senator Gbehzohngar Findley to the key post of foreign minister.

Findley began 2017's presidential campaign supporting Sirleaf's vice-president, Joseph Boakai, who lost to Weah in December.

But he switched allegiance in August, resigned from the party and began openly backing Weah as it became clear that Sirleaf would not campaign for Boakai.

Sirleaf faced accusations she secretly supported Weah, eventually leading to her expulsion from the Unity Party last month.

Elsewhere, the chief of staff of Liberia's armed forces, Major General Daniel Ziankhan, becomes defence minister, while his deputy, Brigadier General Charles Johnson, succeeds him in the position.

Johnson captained the army team that played Weah's veterans' side in a friendly game on Saturday, when he told AFP that Weah was "already started to hear some of the challenges that we are experiencing."

Meanwhile members of Sirleaf's transition team including Information Minister Eugene Nagbe, Education Minister George Werner, Sirleaf's stepson Varney Sirleaf, and the heads of the police and government services, remain in their posts for now.

The handover from Sirleaf to Weah represents Liberia's first democratic transfer of power since 1944, and cements impressions Liberia has finally moved on from a war that killed around a quarter of a million people between 1989 and 2003.