Lawmakers are pushing for billions in federal funding to boost global COVID-19 vaccine manufacturing in Democrats’ coming $3.5 trillion package, arguing that the Biden administration needs to do more to fight the pandemic worldwide and prevent dangerous new variants from forming.

A group of 116 Democratic lawmakers, including more than half of the House Democratic Caucus, wrote to congressional leaders and President Biden last month, calling on them to back $34 billion to increase global manufacturing of COVID-19 vaccines and to help distribute the vaccines around the world.

The push comes as health experts increasingly call on the administration to do more to vaccinate the world, as many countries have still only vaccinated a small percentage of their population, providing fertile ground for new variants to develop that could threaten everyone, including Americans.

But backers of the push in Congress say they have yet to receive firm commitments on the issue from either congressional leadership or the White House.

“No one’s made any commitments to me about it,” said Rep. Tom Malinowski (D-N.J.), one of the leaders of the letter, saying he had spoken to Speaker Nancy Pelosi (D-Calif.) and “everybody I’ve spoken to understands the need.”