Malawi's Peter Mutharika vowed to root out government corruption and rebuild an ailing economy after he was sworn in on Saturday for a second term as president of the southern African nation.

Mutharika, 85, secured more than 56% of votes last month, defeating outgoing president Lazarus Chakwera, 70, who took 33%. Voters rejected Chakwera after five years of worsening economic crisis in one of the world's poorest countries.

The September 16 vote marked the fourth presidential contest between Mutharika and Chakwera.

CEREMONY IN BLANTYRE DRAWS LARGE CROWD

Mutharika took the oath of office in a stadium in the commercial city of Blantyre, packed with supporters dressed in the Democratic Progressive Party's blue and white colours, as well as government officials and African heads of state.

In his inaugural address, he said his administration was inheriting a country in economic crisis.

Malawi is facing acute food shortages, cost-of-living pressures, and a lack of foreign exchange that has crippled businesses and led to persistent fuel shortages, he said.

"There is no money in government. Borrowing is extremely high, and nobody knows where the borrowed money has gone," he said.

But he pledged improvements, saying: "We will fix this country."

"I don't promise you milk and honey. I promise you hard work, tough and painful decisions," he said. "The honeymoon of looting government is over!"

Mutharika also appealed to the international community for investment. He addressed U.S. President Donald Trump directly, saying he would soon send a delegation to America to discuss his country's prospects, especially after cuts in U.S. foreign aid.

Chakwera's Malawi Congress Party said in a statement that although the outgoing president was absent from the inauguration, he wished Mutharika success and good health.