Bill Gates is personally lobbying Trump administration officials to keep funding health programs worldwide, from childhood vaccination to HIV treatment, and warning that his foundation cannot step in to fill gaps, two sources familiar with the matter told Reuters.

Gates, the billionaire Microsoft (MSFT.O) co-founder turned global health philanthropist, met with the National Security Council as well as Republican and Democratic lawmakers in recent weeks to press that case, the sources said.

Soon after his January 20 inauguration, President Donald Trump moved to dismantle the US Agency for International Development, cutting more than 80 percent of contracts and freezing billions of dollars for everything from emergency food assistance to malaria prevention.

The Trump administration, led by the State Department, is reviewing what kinds of foreign aid will remain under its “America First” policy, with a list of around 30 global health projects for consideration, one of the sources said.

“Bill was recently in Washington DC meeting with decision makers to discuss the life-saving impact of US international assistance and the need for a strategic plan to protect the world’s most vulnerable while safeguarding America’s health and security,” said a spokesperson for the Gates Foundation, his charitable organization.

Gates told the officials he met with that his foundation cannot replace the role of the US government, the sources said. Gates Foundation directors have also said publicly that no foundation has that capability.

At the same time, many Gates Foundation top priorities like eradicating polio and fighting malaria will be hit by the US pullback. In such cases, the Foundation would need to decide if and how it can keep those programs on track, one source close to the organization said.

Gates’ discussions focused on organizations such as Gavi, the Vaccine Alliance, as well as the Global Fund to Fight AIDS, Tuberculosis and Malaria, among others.

They are on the shortlist for review by Secretary of State Marco Rubio and Trump. The US gives around $300 million annually to Gavi, and more than $1 billion to the Global Fund.

Drugmakers are urging the Trump administration and EU officials to exclude medical goods from expanding tariff wars.

The Global Fund declined to comment for this story, and Gavi said only that it had not had a termination notice for its main US funding contract. The White House and State Department did not immediately respond to requests for comment.

Several projects under the President’s Emergency Plan for AIDS Relief (PEPFAR) are also on the review shortlist, the source said.

At the National Security Council, Gates also pushed for the US to continue to support the World Health Organization, which Trump moved to exit on day one of his administration, as well as efforts to eradicate polio.

Established in 2000, the Gates Foundation has an annual budget of more than $8 billion. Gates has met regularly with security officials in previous administrations on key areas like malaria or COVID-19.

He met with Trump at a dinner in December, before the inauguration, and the White House in early February after the USAID cuts were first announced, according to an NBC report.