Answer
It is not permissible to kill a disbeliever if he does not accept Islam. However, in a situation of jihad, if the disbelievers are conquered, they will be invited to Islam. If they refuse to accept Islam, they will be ordered to give jizya (tax). If they refuse to give jizya, then only will they be killed.
Was salaam
Mufti E Desai
Fatwa Dept.