ISTANBUL 

Microsoft co-founder Bill Gates announced Thursday he will donate "virtually all" of his estimated $200 billion fortune in the next two decades, with plans to permanently close the Bill & Melinda Gates Foundation by the end of 2045.

Gates outlined his accelerated philanthropy timeline in a blog post, marking a significant change from the foundation's original charter, which planned closure decades after his death.

"During the first 25 years of the Gates Foundation - powered in part by the generosity of Warren Buffett - we gave away more than $100 billion. Over the next two decades, we will double our giving," wrote Gates, whose net worth is $113 billion according to Forbes.

The 69-year-old philanthropist indicated the foundation's future funding will focus on three key goals: eliminating preventable maternal and child deaths, eradicating deadly infectious diseases and helping hundreds of millions escape poverty.

Gates encouraged wealthy individuals to consider accelerating their giving, calling it "a profoundly impactful way to give back to society."

"Today's announcement almost certainly marks the beginning of the last chapter of my career, and I'm okay with that," Gates noted, expressing hope for "a future where everyone everywhere has the chance to live a healthy and productive life."