Actor/rapper Jaden Smith is doubling his efforts to give the people of Flint, Michigan access to clean water by donating a second filtration system in Ellen DeGeneres' name.

The Karate Kid star, whose parents are Will and Jada Pinkett Smith, has been focusing his charity efforts on the city of Flint, where residents have been exposed to lead-contaminated water due to a change in river source in 2014.

Authorities are still working to replace the corroded water pipes, but the huge job was previously not expected to be completed until at least 2020.

Jaden and his dad have been sending crates of their JUST water products, which are packaged in paper-based cartons, to the area so locals can pick up the vital resource for free, and earlier this year (19), the 20 year old launched a new mobile water filtration system, which was installed at a church in Flint.

Now the youngster has unveiled plans to provide another mobile unit for Flint residents, and this time, he's donating the device in honour of comedienne and fellow philanthropist Ellen.

Jaden shared the news during an appearance on America's The Ellen DeGeneres Show, which aired on Friday (07Jun19).

"I actually got you a present...," he told the host. "I got you a water filtration system in your name that I'm actually gonna donate and put into Flint for you. I put the Ellen logo on it, the whole thing."

Touched by the present, Ellen said, "That's amazing, you're so sweet."

"We've only done one (machine so far), so this is the second one we've ever done...," Jaden explained. "We're putting this actual box in Flint, providing clean water for people..."

Jaden and Will co-founded the JUST water company in 2015 in a bid to reduce the use of plastic bottles in favour a more eco-friendly option.