The Love Actually star travelled to the nation in his role as an Oxfam ambassador to witness how the organisation has helped locals.
Nighy wants the U.K. government to invest extra cash into programs to address the HIV/AIDS epidemic in the country, and has urged bosses at pharmaceutical companies to make more medicines available.
Speaking to British TV host Kate Garraway, he says, ""I've been in Malawi, which is one of the poorest countries in the world. I went there on behalf of Oxfam, for whom I'm an ambassador, and I visited a hospital and I visited a school, and I visited other places, an HIV centre, with a view to witnessing the fact that the money does get through and also to come back to report that they need help and they need it desperately.
""Next week is the government's Autumn Statement (an address made to parliament about economic forecasts) and we are hoping passionately that they will announce that they are extending their aid to Malawi and that there is longterm aid in the works because they need longterm stuff...
""They need to be able to plan for the future. There are a million people in Malawi with AIDS currently, 650,000 of them don't have the medicines. It's a matter of life and death... it's a death sentence.
""We have everything, we have to deliver it to them. We have all the medicines they need, the pharmaceutical companies and everybody could combine to make this problem go away.""