Bill Gates and British Chancellor George Osborne have pledged £3 billion ($4.3 billion) to eradicate malaria, a mosquito-borne disease that killed an estimated 438,000 people last year. Gates and Osborne announced the funding in a piece for The Times of London on Monday, saying the sum will go toward research and other eradication efforts over the next five years.

"When it comes to human tragedy, no creature comes close to the devastation caused by the mosquito," Gates and Osborne wrote. "We both believe that a malaria-free world has to be one of the highest global health priorities."

"We are optimistic that in our lifetimes we can eradicate malaria."

Eliminating malaria has been a priority for the Bill and Melinda Gates Foundation, the Microsoft founder's philanthropic organization. In November, the foundation partnered with the UK government to establish the Ross Fund, a £1 billion initiative to support the development of vaccines, insecticides, and other efforts to combat malaria and infectious diseases. For the fund announced this week, the UK government will provide £500 million a year for the next five years, while the Bill and Melinda Gates Foundation has committed $200 million for this year.

According to the World Health Organization, there were approximately 214 million malaria cases across the world in 2015, with the vast majority (89 percent) affecting Sub-Saharan Africa. Of the estimated 438,000 deaths, most were children under the age of five. Eradication and control efforts have shown progress over the past 15 years, though they've been hampered by growing resistance to drugs and insecticides.

In their article, Gates and Osborne argued that unless new insecticides are introduced by 2020, "the situation will become critical and deaths could surge," stressing the need for collaboration across governments, charities, and the private sector.

"We are optimistic that in our lifetimes we can eradicate malaria and other deadly tropical diseases, and confront emerging threats, making the world a safer place for all," the two wrote.

An earlier version of this article incorrectly stated the amount of money that the UK government will provide for the fund. It has been corrected.