re-establish

US /ˌriː.ɪˈstæb.lɪʃ/
UK /ˌriː.ɪˈstæb.lɪʃ/
1.

thiết lập lại

to start having a relationship with or communicating with another person, company, country, or organization again, after a previous relationship or communication has ended:

:
We lost touch years ago, but I have just written to them to try to re-establish contact.