Can he travel to a kaafir country for the sake of upholding family ties?

It is not permissible to travel to a kaafir country
except for a valid reason such as studying to acquire knowledge or skills that are not
available in a Muslim country, or for medical treatment. But the traveller should have
sufficient religious commitment to protect him from temptation and sufficient knowledge to
protect him from doubts. Keeping in touch with relatives and upholding the ties of kinship
can be achieved through lesser means; you can call them by phone, or correspond with them
in any fashion, or send greetings and gifts, and so on. A person should not expose himself
to the risks of travelling to a kaafir country and committing sin for the sake of
something that may be achieved through other means. And Allaah knows best.