Surah 3:28
Believers should not take disbelievers as guardians instead of the believers - and whoever does so will have nothing to hope for from Allah - unless it is a precaution against their tyranny. And Allah warns you about Himself. And to Allah is the final return.

The Prohibition of Supporting the Disbelievers

(unless you indeed fear a danger from them) meaning, except those believers who in some areas or times fear for their safety from the disbelievers. In this case, such believers are allowed to show friendship to the disbelievers outwardly, but never inwardly. For instance, Al-Bukhari recorded that Abu Ad-Darda' said, "We smile in the face of some people although our hearts curse them." Al-Bukhari said that Al-Hasan said, "The Tuqyah is allowed until the Day of Resurrection." Allah said,

In Islam, taqiyya (Arabic: تقیة, romanized: taqiyyah, lit. 'prudence')[1][2] is a concept that refers to a Muslim concealing their faith or religious identity to protect themselves from danger.
Taqiyya