Thanks for the offer but importing the item to Japan has become more strict.
I appreciate the offer but importing to Japan has become more strict.
「日本ではこの品物の輸入が厳しくなった、お気持ちだけ。」
「日本ではこの品物の輸入が厳しくなった」 = Importing the item to Japan has become strict.
「お気持ちだけ」= Thanks for the offer; thanks for the thought; (I) appreciate the thought
になると思います。
Importation of this item has become more strict in Japan so it’s hard to take, but thank you for your kindness.
I can’t take this item to Japan because importation laws have become more strict, but I appreciate the thought.
「この品物の輸入が厳しくなった」は”importation of this item has become more strict”です。”I can’t take it”または”it’s hard to take”は「持って行けない」と「持って行くのが難しい」という意味です。
相手のプレゼントなどを断るけどお気持ちだけを受け取りたいときは”but thank you for your kindness”や”but I appreciate the thought”などがよく使うフレーズです。