Cadeiriwyd y cyfarfod gan Brif Weinidog Gogledd Iwerddon (y cyn-Brif Weinidog erbyn hyn) y Gwir Anrhydeddus Arlene Foster ACD, a'r dirprwy Brif Weinidog, Michelle O'Neill ACD. Ymysg y mynychwyr eraill, a oedd yn y cyfarfod naill ai’n bersonol neu'n rhithwir, roedd Canghellor Dugiaeth Caerhirfryn, y Gwir Anrhydeddus Michael Gove AS; Ysgrifennydd Gwladol Gogledd Iwerddon, y Gwir Anrhydeddus Brandon Lewis AS; An Taoiseach, Micheál Martin TD; An Tánaiste, Leo Varadkar TD; Y Gweinidog Materion Tramor a'r Gweinidog Amddiffyn, Simon Coveney TD; Prif Weinidog yr Alban, y Gwir Anrhydeddus Nicola Sturgeon ASA; a Phrif Weinidogion Jersey, Guernsey ac Ynys Manaw.
The (now former) First Minister of Northern Ireland, the Rt Hon Arlene Foster MLA, and the deputy First Minister, Michelle O’Neill MLA, chaired the meeting. Other attendees, who attended either in person or virtually, included the Chancellor of the Duchy of Lancaster, the Rt Hon Michael Gove MP; the Secretary of State for Northern Ireland, the Rt Hon Brandon Lewis MP; An Taoiseach, Micheál Martin TD; An Tánaiste, Leo Varadkar TD; Minister for Foreign Affairs and Minister for Defence, Simon Coveney TD; the First Minister of Scotland, the Rt Hon Nicola Sturgeon MSP; and the Chief Ministers of Jersey, Guernsey and the Isle of Man.