Tom Hart is the North America executive director of The ONE Campaign, a policy and advocacy organization of more than 8 million people taking action to end extreme poverty and preventable disease, particularly in Africa. The opinions expressed in this commentary are his own.

(CNN) After 15 years of strong, bipartisan American leadership and incredible progress in the global fight against AIDS, the Trump administration appears ready to trade the iconic red ribbon for the white flag of surrender.

That's the conclusion of a new ONE Campaign report released this week. Working with some of the nation's leading experts in the global fight against AIDS, ONE's policy experts analyzed the consequences of President Donald Trump's first budget proposal, which included a roughly $800 million cut to bilateral HIV/AIDS efforts , and a new strategy issued by the State Department for the government's transformative flagship global AIDS program, the President's Emergency Plan for AIDS Relief (PEPFAR).

The lower funding level would force PEPFAR to stop putting additional people on HIV treatment in some of the world's highest-burden countries, like South Africa and Nigeria, as it shifts resources away from dozens of "non-priority" countries.

Despite remarkable progress, 15.8 million people living with HIV do not have access to treatment , and many of those individuals live in countries whose bilateral AIDS assistance would be cut under the Trump administration's budget proposal.

We need to be doing more -- not less.

In fighting the global epidemic, there is simply no substitute for getting more people on treatment. Treatment allows people living with HIV to live healthy and productive lives, and has also proven to be a powerful tool for preventing new HIV infections -- the reduction of mother-to-child transmission by putting pregnant and breastfeeding women on treatment is proof. When properly adhered to, AIDS treatment reduces the amount of human immunodeficiency virus in a person's body to levels low enough that they are no longer infectious.

Stopping the treatment of additional people could result in nearly 300,000 deaths and more than 1.75 million new infections each year, and would almost certainly trigger a resurgence in the epidemic. It would also make it mathematically impossible to control the epidemic globally, putting out of reach critical treatment targets for getting ahead of the disease before Africa's young-adult population doubles in 2050.

Whether intentional or not, it would mean surrendering the global AIDS fight that the US has led.

When President George W. Bush created PEPFAR in 2003, the continent of Africa was under attack, and people with AIDS lived without hope. That year alone, 3 million people died and 5 million people became infected with HIV.

By partnering with the hardest-hit countries to provide lifesaving services to patients, PEPFAR has transformed the AIDS landscape. The program contributed to a 47% decrease in AIDS-related deaths since its inception, has saved more than 11 million lives , and is why over 2 million babies have been born HIV-free to HIV-positive mothers. In 2016, 2.4 million people started AIDS treatment (over half of whom were supported by PEPFAR), compared with just 1.5 million in 2010.

JUST WATCHED Rescuing Cape Town's 'left behind' children Replay More Videos ... MUST WATCH Rescuing Cape Town's 'left behind' children 02:45

Those to whom PEPFAR has given hope are living monuments to 15 years of passionate bipartisan cooperation in Washington. Republicans and Democrats have stood in lockstep to ensure PEPFAR had the resources it needed to turn the tide and help the world get ahead of the disease.

World AIDS Day was Friday, and for the first time in more than a decade, the global AIDS community will mark the day by not only celebrating the incredible progress we have made against the disease, but worrying that America's commitment to ending AIDS is waning.

Join us on Twitter and Facebook

We are finally getting ahead of this deadly disease, but the gains we've made are fragile. They need to be built-upon, not squandered.

President Trump should restore full funding for PEPFAR and the Global Fund in his budget request for 2019, but if he proposes another cut, Congress should once again push it aside. PEPFAR must be given the resources it needs to stem the disease ahead of Africa's expected population boom. Failure to expand treatment could mean abandoning the historic opportunity to end the AIDS epidemic as a global health threat forever.

Our response in the global fight against HIV/AIDS should be to lead, not surrender.