Abortions are illegal in Argentina and in pretty much all of South America. So I don't see how his decree could affect women in Argentina.
So since you didn't read the article, here's the gist of it, directly quoted:
"Trump reinstated the Mexico City policy, also known as the global gag rule, which was first put in place by President Ronald Reagan in 1984. It prohibits giving U.S. funding to international nongovernmental organizations that offer or advise on a wide range of family planning and reproductive health options if they include abortion ― even if U.S. dollars are not specifically used for abortion-related services.
The United States spends about $600 million a year on international assistance for family planning and reproductive health programs, making it possible for 27 million women and couples to access contraceptive services and supplies.
None of that money is spent on performing abortions."
Someone posted a question asking how Trump has done anything so far that affects women. Clearly, this order affects women worldwide, specifically poor, uneducated women, who are typically the ones who don't have access to any reproductive health services, not limited to abortion. Does it really seem like a good idea to deny these kinds of services and information (not just abortion) to women who likely can't afford to have unlimited children?
Finally, abortion may be technically illegal in Argentina and many countries across South America, but all that means is that women with access to money are able to access abortion providers (whether illegal or across borders where it is legal) and poor women are stuck.
Seems to me like worldwide access to family planning information and contraception for both wealthy and poor women is a human right and should not be signed away at the stroke of a pen by a male billionaire with five kids by three different women.