The U.S. would have done that a long time ago but I don't think the economic situation of the 90s to the 2000s would have permitted the AFP from getting the Abrams. This discussion thread from Quora summarizes why MBTs are gamble for the Philippines:Also, I get the feeling the US will simply pressure the Filipino army to buy Abrams over anything else, if they ever considered getting MBTs.
What main battle tank will the Philippines have?
Answer (1 of 4): Using a Main Battle Tank in the terrain of the Philippines will be difficult and counter-productive unless used only in limited areas such as highly urbanized environments and relatively flat terrain that has firm ground. Such a heavy tank of more than thirty to forty tons will n...
www.quora.com
Meanwhile, there was a discussion in PH defense forum that the Philippines may look at older M1 Abrams tanks (the original variant used in the 80s-90s, not the M1A1 or the M1A2) but none has materialized so far.
That's because of CAATSA. If the AFP wanted to get surplus Russian tanks, the best time to have done it was before 2017.In the meantime, the current administration has plans to buy tanks from Russia, AFAIK no steps has been done.