The Japanese and English transcript are well constructed. Unfortunately, it seems he just read the script the night before the his speech. Obviously he did not practice hard enough, so he should have done it in Japanese. Convincing speech in Japanese would have been much more persuasive than his horrible English speech. His speech did not have any flow; just flat 14 minutes mumbling was really painful. He should have known that cramming the speech on the night before the talk is not enough. If he thinks he did well, then he is hopeless. I hope they provided translation to the audience since I doubt people understood his speech without it. I am sure he did not understand his own speech well by himself.
Many Japanese who prepared this document should have been disappointed with his speech. It was painful to listen. Broken English is totally fine in informal settings, but not at a UN meeting as a representative of the country. Fortunately the auditorium was more than half empty.