Why not remove the tariffs permanently?

The Government announced:

New Zealand will temporarily remove tariffs on all medical and hygiene imports needed for the COVID-19 response.

Trade and Export Growth Minister David Parker and Commerce and Consumer Affairs Minister Kris Faafoi said today that the New Zealand Customs Service will apply tariff concessions to all diagnostic reagents and testing kits used for COVID-19 testing and soap imports in the first instance.

Officials are in the process of identifying other medical and hygiene products needed for the COVID-19 response, and further tariff concessions will follow shortly.

“There is increased global demand for these medical and hygiene products and some countries are restricting their exports of them. We want to make sure that New Zealand has the most straightforward and cost effective access possible to the supply of the goods needed to respond to COVID-19,” Kris Faafoi said.

Totally in favour of this, but why put the tariffs back on in a few months? Do we really want to increase the cost of medical and hygiene products used by New Zealanders?