BERLIN — A German border region is preparing to hand out potassium iodide tablets to residents who want them in case of an accident at a nuclear power plant in Belgium that has caused friction between the two countries.

Local officials in the Aachen area received permission from the regional government to distribute the tablets as a precaution amid longstanding concerns in Germany over the safety of the Tihange plant, less than 70 kilometers (43 miles) away. They’re meant to prevent thyroid cancer in case of radioactive contamination.

From Friday through Nov. 15, people under 46 can apply online for a coupon for the iodine tablets, which they can pick up free at pharmacies.

Germany plans to switch off all its nuclear reactors by 2022 and already has shut its oldest plants.