A senior U.S. diplomat overseeing ocean policy welcomed additional funding and interest from Congress.
But he cautioned the lawmakers that the Trump administration has concerns that the World Bank's Problue fund could work to restrict plastics production and use.
"We're a little concerned with their advocacy to reduce upstream production and use of plastics that could undermine the growing recycling market," said Jonathan Moore, the State Department's principal deputy assistant secretary in the bureau of oceans and international environmental and scientific affairs.
He suggested another multilateral organization that the U.S. government works with, the Global Environmental Facility, as a potential "strong alternative" mechanism to Problue.
GEF's website described it a donor fund set up during the 1992 Rio Earth Summit to support conservation efforts in developing countries.
"We're a member of the GEF Council," Moore told the senators. "We've had a long history of shaping its programming to advance U.S. interests."
Graham said he wanted Moore to give feedback to the committee on how a potential U.S.-led fund would work and whether the U.S. should join the Basel Convention or boost involvement in the Problue fund.
"Being left out is not a good place to be," Graham said. "We're the biggest fish in the sea, no pun intended, and we need to get in the game here.
"I really think this committee is very inclined to put some money in a global fund," Graham said. "This is a good place for this committee to lay down a new marker and put some money that would entice others."
Graham's office did not respond to a request for comment on more details on a fund.
Problue launched in 2018 with $150 million in pledged funding. It's modeled on a World Bank fisheries fund that leveraged more than $1 billion over its lifespan, according to Problue's website.
Sen. Tom Udall, D-N.M., supported Graham's message that the U.S. should be more involved with global efforts.
"I think the thrust of what you're saying is very important for the [Donald Trump] administration to hear," Udall said. "Thank you for that comment."
Udall believes the U.S. administration has been too supportive of development policies and trade agreements that favor petrochemical investments and has lined up against efforts by more than 80 countries for a new global agreement around the impacts of plastic.
"Despite what has been said here today, it's very clear to me that U.S. participation in all international processes to develop regulations on plastic production and impose limits on plastic waste exports have been counter to the efforts of the broader international community," Udall said.
Sen. Jeanne Shaheen, D-N.H., also said she wanted more international efforts.
"This administration has pulled the United States away from a number of international cooperative efforts," she said. "An issue like how do we get rid of plastics worldwide is something that we've got to cooperate with other countries on."
Moore said the U.S. works in many global organizations, including the U.N. Environment Assembly, on plastics issues, and he noted that U.S. aid programs are working on plastics issues in countries such as Vietnam and Indonesia.
He said the government is very concerned about the issue, and also works with private sector organizations like the Alliance to End Plastic Waste, as well as a recent partnership on ghost fishing gear.
"It is a global problem with global consequences," Moore said. "We need innovation in materials and design, changes in behavior and significant improvements in waste management systems."
Graham and Senator Patrick Leahy, D-Vt., both said the U.S. government currently spends about $12 million a year in its foreign aid budget toward combating marine plastics. That number apparently includes a five-year, $48 million "Clean Cities, Blue Ocean" program launched last year.
And both said they wanted to increase that funding. Leahy, the ranking Democrat on the appropriations committee, suggested that $12 million figure is very small for the global scope of the problem.