Facebook founder Mark Zuckerberg said Tuesday he and his wife are donating an additional $100 million to help local election administrators, while brushing aside accusations of partisan motives.

The new donation is on top of $300 million Zuckerberg and Priscilla Chan pledged last month and will pay for infrastructure including voting equipment, PPE for poll workers and additional polling staff, the entrepreneur said in a Facebook post.

"Between Covid and insufficient public funding for elections, there are unprecedented challenges for election officials working to make sure everyone can vote safely this year," he wrote.

Zuckerberg said the additional funds were being added due to "a far greater response than we expected" from election officials in the program being administered by the nonprofit Center for Tech and Civic Life.

Facebook founder and CEO Mark Zuckerberg and his wife Priscilla Chan, seen here in 2016, are donating some $400 million to help local US election administrators
Facebook founder and CEO Mark Zuckerberg and his wife Priscilla Chan, seen here in 2016, are donating some $400 million to help local US election administrators AFP / John MACDOUGALL

"So far, more than 2,100 local election jurisdictions have submitted applications to CTCL for support," he said.

Zuckerberg, with a personal net worth estimated at some $90 billion, said there had been "multiple lawsuits filed" seeking to block the donation "based on claims that the organizations receiving donations have a partisan agenda. That's false."

He said the funds "are being allocated by non-partisan organizations" from urban and rural jurisdictions around the country, with many from districts with fewer than 25,000 registered voters.

"To be clear, I agree with those who say that government should have provided these funds, not private citizens," Zuckerberg wrote.

"I hope that for future elections the government provides adequate funding. But absent that funding, I think it's critical that this urgent need is met."