Trump, who prizes his relationship with North Korean leader Kim Jong-un, said the launches did not violate an agreement and were in line with what others were doing.
Abe said the launches violated U.N. resolutions.
Launches of short-range ballistic missiles on Saturday were the seventh by North Korea since Trump and Kim met at the inter-Korean border in June.
The launches have complicated attempts to restart talks between U.S. and North Korean negotiators over the future of Pyongyang's nuclear weapons and ballistic missile programs.