This is as he was inaugurated as the fifth leader of the southern African state in the wake of a disputed election.
Mutharika, who was announced winner of the May 20 election last week, also extended an olive branch to his predecessor, Joyce Banda, who at one point disputed the validity of the vote and demanded a re-run.
Banda did not attend Mutharika's inauguration in the commercial capital, Blantyre.
"I look forward to shaking hands with her to bury the past. I come to her with an olive branch. Don't let it drop," Mutharika said in his inauguration speech.
(READ MORE: Malawi's post-election developments)
Mutharika, 74, is the brother of the President Bingu wa Mutharika who died in office in April 2012.
Banda took over after Mutharika's death and tried to rebuild an economy hammered by fuel and dollar shortages, but prices have soared since she devalued the kwacha currency on the advice of the International Monetary Fund (IMF).
In January, the IMF rated Malawi's economic performance "broadly satisfactory" after completing its third and fourth reviews under a credit facility, enabling the Fund to disburse around 20 million US dollars.
But recent revelations of corruption - dubbed 'Cashgate' in the Malawi media - led key donors to withhold millions of dollars in budget support to a country that has traditionally relied on foreign aid for 40 per cent of its budget.
Mutharika said his administration would target an annual economic growth rate of 7 per cent.