Portsmouth Atlantic Compact was established in 2013. It includes:
- Portsmouth Virginia – Sister City Established 1982
- Portsmouth, New Hampshire – Friendship Link Established
- Portsmouth, Rhode Island – Friendship Link Established
This compact was established by the four Portsmouth cities, with the aim of promoting cultural and educational activities across the similar named town and cities. Our Lord Mayor visited the three US Portsmouth cities in 2013 when the compact was established. Our Lord Mayor visited them again in 2018 as part of a wider visit during his Mayoral year.
The cities join together with all those sharing similar time zones for a festive greeting hosted by the Lord Mayor.