輸入制限は両国間により親密な関係を作る支障になる。

。

Import restrictions hinder the creation of closer relations between the two countries.

Literal

Import restrictions [topic-は] both-countries-between [at-に] more intimate relations [object-を] create obstacle [become-になる].

支障になる ('to become an obstacle') is a formal expression for hindering. 両国間 (りょうこくかん) uses the suffix 間 ('between'). より modifies 親密な ('intimate'), creating a comparative without the usual より...ほうが structure.