Tensions are mounting between Brussels and Beijing after the EU agreed to "strongly encourage" mandatory Covid testing for tourists arriving in Europe from China.
The decision has angered Beijing. A spokesperson from the Chinese Foreign Office said it thinks the decision discriminates against its citizens.
A surge in Covid-19 cases following the relaxation of strict virus restrictions has seen China's health system overwhelmed. As a result, European countries are raising their defences.
In a tweet, the German Foreign Ministry urged its citizens to avoid travelling to China unless necessary.
Meanwhile, Portugal has announced that from Sunday, all passengers arriving from China will have to show a negative Covid-19 test before boarding the plane.
Belgian authorities have also decided to follow the advice. At Brussels airport, wastewater from planes arriving from China is tested to prevent new variants of Covid from appearing.
Several other EU nations including France, Italy and Spain have already announced Covid test requirements on travellers coming from the Asian nation.
The United States and Japan are among the non-European countries to have brought in similar measures.