Angelina Jolie has met with the Archbishop of Canterbury

Speaking about the convention, Justin posted on Twitter: "Privilege to welcome UNHCR Special Envoy Angelina Jolie. Discussed refugee crisis, South Sudan and prevention of sexual violence in conflict (sic)"

During the visit, the 'Maleficent' star - who has six children, Maddox, 15, Pax,13, Zahara, 12, Shiloh, 10, and eight-year-old twins Vivienne and Knox, whom she raises with estranged husband Brad Pitt - and Justin spoke at length about what could be done about the humanitarian crisis in South Sudan where people are starving from famine due to the civil war which has ravaged the African country.

This is not the first time Justin and Angelina have met; the pair joined forces two years prior at the launch of the Center for Peace and security at the London School of Economics, which saw Angelina converse with significant figures from across the globe about bringing an end to sexual violence in conflict.

Justin has previously praised the star for taking "great personal risks" and spoken "authentically" about the topic.

Speaking at the time, he said: "The role of the U.N. Secretary General's Special Envoy on Refugees, Angelina Jolie, is one that has been extraordinary. What she said just now sums up so beautifully the issues we are facing, and puts it so precisely in terms of the challenge that there is. It's wonderful that she has committed her time, her energy, and has taken great personal risks in order to be able to speak authentically as to what she's done."