Trade restriction can sometimes be necessary to make the economy grow. Some people become too accustomed to the items that are from different countries that they forget to love their own products. They become too excited about the products from other countries that those that are available in their own country are already disregarded.
Trade will always help countries develop better relations. There are also a lot of other benefits that can be achieved with proper trading but it is not unusual to restrict trade from time to time to help local businesses grow.