Chilima told AFP in an interview that he no longer speaks to President Peter Mutharika, and he alleged that corruption had worsened under the current government.
Chilima was Mutharika's running mate in the 2014 election, but the two have fallen out spectacularly.
"I send my communication (to the president) as notification that I am travelling -- that is as much communication as there is," Chilima said, adding there was "no relationship" between the two men.
Chilima, 45, a wealthy former businessman, is seen as a young challenger to Mutharika, 79.
He quit the ruling Democratic Progressive Party (DPP) last year and set up the United Transformation Movement (UTM) to contest the election.
Under Malawi's constitution, the vice president cannot be sacked by the president.
Speaking at his grand official house decorated with oil paintings and surrounded by extensive gardens in the capital Lilongwe, Chilima told AFP that corruption and bad leadership had worsened poverty in one of the world's poorest countries.
"People in leadership positions... have known what needed to be done but they have done the opposite," he said.
"There is serious plunder of public resources that are meant to improve quality of life. Because of plunder, we have under-sourced programmes that would have brought about a better quality for the citizens.
"We need to have a situation where everybody can eat three decent meals a day. If we cannot feed ourselves, we really cannot do any meaningful developmental activities."
About half of Malawi's 18 million population live below the poverty line, according to the World Bank.
Former business executive
Chilima, a former executive with Airtel mobile and other international companies, said poverty could be tackled by modernising Malawi's agriculture sector and boosting tourism and construction.
Despite being a senior member of the government, he railed against the graft and patronage that he said was plaguing Malawi.
"Whether we have accomplished fully what we had set up to accomplish? The answer is no. Corruption is worse," he said.
"It's politics of patronage and appeasement. Nepotism is one of the evils that we have to fight outside corruption and abuse of office.
"It's not a secret that there is corruption in this country, and it must be dealt with.
"We need to speak against nepotism.... You find it in procurement, in recruitment and promotions in the public service."
President Mutharika won the election in 2014 two years after his brother, Bingu wa Mutharika, died while serving as president.
Malawi has been beset by corruption scandals, including an official anti-graft report last year that accused Mutharika of receiving money from a contractor supplying food rations to the police.
The president himself was elected after his predecessor Joyce Banda was embroiled in the "cashgate" scandal in which ministers and government officials syphoned off tens of millions of dollars of public money.
Foreign aid -- on which the southern African state is dependent -- was temporarily frozen over the revelations.
Banda returned to the country in April after four years of self-imposed exile and is also set to run in the elections, scheduled for May 21.
Food shortages, power outages and ballooning external debt have hurt the president's popularity.
But Chilima's chances of launching a serious challenge to Mutharika remain uncertain, and he did not rule out a deal with Banda.
"A meaningful alliance is a good idea," Chilima, a devout Catholic, said, adding his party "desired a country of equal opportunity. We desire a country where citizens are happy."