One of the biggest sources of domestic criticism has been the absence of a joint text on the agreement, observers say.
While Ishiba has touted the trade deal reached last month as benefiting both nations, he also acknowledged on Monday that the real challenge would be in its implementation.
“Some say that carrying the trade deal out is harder than agreeing on it. I humbly seek your continued support on this,” he told a parliamentary session.
The agreement, reached just before an August 1 deadline and after intense negotiations, has been credited with averting a potential trade crisis for Japan.
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