NEW YORK, Feb. 12 (Xinhua) -- Bill Gates, co-chair of the Bill & Melinda Gates Foundation, said Tuesday that exciting progress against poverty and disease around the world has been made in 2018, and China has been a major contributor to this progress.

In a video speech exclusively broadcast via Xinhua, Gates said over the past four decades, China lifted over 800 million people out of poverty and became the second largest economy in the world. Now, it's stepping up its efforts to help solve some of the toughest challenges in the rest of the world.

He said during his recent visit to China, he attended the Reinvented Toilet Expo and once again saw China's innovation capacity, with companies showcasing game-changing products that will benefit billions who today do not have access to safe sanitation.

He met Chinese scientists who are developing new drugs to tackle infectious diseases like tuberculosis that affect the poor, and talked with Chinese partners who are sharing lessons from China's own development, so that African countries can make progress on vital priorities such as strengthening health systems and controlling deadly diseases like malaria, and also improving agricultural transformation.

"I believe in China's ability to help hundreds of millions of young people in the world's poorest countries fulfil their potential. As we usher in the New Year, our foundation is committed, as always, to supporting China in building a better future for all," he said.

The video coincides with the release of Bill and Melinda Gates 2019 Annual Letter, in which they focussed on nine surprises and what can be learned from them.

"Some surprises help people see when the status quo needs to change. Others underscore that needed transformation is already happening," he said.

"In 2018, we continued to see exciting progress against poverty and disease around the world. But as many nations turn inward, we risk losing sight of crucial global priorities, especially the need to invest in the health and education of young people," Gates said.

He said one surprise they share in the letter is how much Africa is the world's youngest continent. Between now and the end of the century, an increasing proportion of young people will come from countries on the African continent.

"Whether we ensure that these people (who) grow up healthily and well-educated and have the opportunity to thrive will determine the future trajectory of the whole globe," he stressed. "We hope observations like these will prod readers to take action to accelerate the progress the world has been making."