Surrounded by a crowd of men, for which he was widely derided on social media once pictures began circulating, Trump signed the policy, initially put in place by the Reagan administration, but was rescinded by the Obama administration in 2009.
"The President, it's no secret, has made it very clear that he's a pro-life president," White House Press Secretary Sean Spicer told reporters at his first daily briefing. "He wants to stand up for all Americans, including the unborn, and I think the reinstatement of this policy is not just something that echoes that value, but respects taxpayer funding as well."
Even during the Obama years, US law banned direct funding for abortion services. But NGOs that performed the procedure were allowed to receive US funding for other programs, including those related to contraception access and post-abortion care.
Now, NGOs that offer or promote abortions as part of their family planning services will be prevented from receiving any assistance from the US Agency for International Development, one of the largest contributors to international development assistance.
Trump's decision was labeled as "catastrophic," leading to women in developing countries "paying the price," according to Marie Stopes International's vice-president and director of the organization's international operations Marjorie Newman-Williams.
According to the charity, the loss of its services during Trump's first term could cause 6.5 million unintended pregnancies, 2.2 million abortions, 2.1 million unsafe abortions, and 21,700 maternal deaths.
The organization also said it will also be prevented from reaching 1.5 million women with contraception every year.
"All the medical evidence, as well as everything we know from our daily interactions with women, is unequivocal: If you take safe abortion services out of the reproductive healthcare package, it exposes women to risk," Newman-Williams said.
"Attempts to stop abortion through restrictive laws -- or by withholding family planning aid -- will never work, because they do not eliminate women's need for abortion," added Newman-Williams. "This policy only exacerbates the already significant challenge of ensuring that people in the developing world who want to time and space their children can obtain the contraception they need to do so."
Marie Stopes International also said that it gave 2,843 general and gynecological checkups and performed 586 contraceptive implant insertions in the wake of the 2015 earthquake in Nepal -- all supported by US funding.
Nancy Northup, president and CEO of the Center for Reproductive Rights,
said in a statement: "Trump's Global Gag Rule will only lead to increases in unintended pregnancies, unsafe abortions, maternal and newborn deaths."
The policy has been enforced off and on since it first took effect in 1985. Democratic administrations have traditionally rescinded the policy, while Republican administrations have reinstated it.
Reaction from Democrats and abortion rights activists was swift.
In a statement issued shortly after the action was signed, NARAL Pro-Choice America slammed the move.
"Donald Trump has turned his anti-women rhetoric into policy, and made it more difficult for women and families all over the world to access vital reproductive care. He really is living up to the lowest of expectations," NARAL's president, Ilyse Hogue, wrote.
New Hampshire Democratic Sen. Jeanne Shaheen took to Twitter to announce that she would put forward a bill repealing the policy permanently. Such a bill would end the cycle of repeals and reinstatements the policy has seen over the years, but would be unlikely to pass a majority-Republican Congress.
Meanwhile, conservatives in Congress and anti-abortion activists are applauding Trump for signing the executive action.
"For yrs, U.S. has debated abortion," Sen. James Lankford, an Oklahoma Republican, tweeted Monday. "At least we can agree no taxpayer should be forced to pay for it."
"President Trump is continuing Ronald Reagan's legacy by taking immediate action on day one to stop the promotion of abortion through our tax dollars overseas." Marjorie Dannenfelser, president of the anti-abortion advocacy group Susan B. Anthony List.
"President Trump's immediate action to promote respect for all human life, including vulnerable unborn children abroad, as well as conscience rights, sends a strong signal about his administration's pro-life priorities."