「米国政府は数値目標を掲げることに反対しておりますが、大変困った考え方です。」という一文を英訳するなら、

We feel it very regretful that the U.S. government has been very reluctant in posting its numerical targets against it.

よりも、

We consider it a matter of considerable regret that the U.S. government has been opposed to making numerical targets public.

の方が適切です。