The Japanese media and opposition lawmakers have suggested that Abe's comments were overkill.
"Contaminated water 'control' running astray," the nationwide Asahi newspaper said in its front-page top story on Saturday.
"Credibility of prime minister's message to overseas is shaking."
Hikariko Ono of the prime minister's office defended Abe's pledge, citing offshore monitoring results showing undetectable radioactivity. The government has stepped up efforts to contain the leaks.