Currently 182 states maintain diplomatic relations with the Holy See. On 9 December 2016 diplomatic relations were established with the Islamic Republic of Mauritania, at the level of the Apostolic Nunciature and Embassy. The European Union and the Sovereign Military Order of Malta are also to be added to the aforementioned states.

There are 88 Embassy Chancelleries based in Rome, including those of the European Union and the Sovereign Military Order of Malta, since during the year the embassies of Palestine – following the entry into effect of the global Agreement between the Holy See and the State of Palestine of 26 June 2015 – and Malaysia. The Offices of the League of Arab States, the International Organisation for Migrations and the United Nations High Commissioner for Refugees are also based in Rome.

During 2016 three Agreements were signed: on 20 May, the Framework Agreement between the Holy See and the Democratic Republic of the Congo on matters of mutual interest; on 8 September, the Framework Agreement between the Holy See and the Central African Republic on matters of mutual interest, and on 22 October, the Framework Agreement between the Holy See and the Republic of Benin regarding the legal status of the Catholic Church, while on 15 October 2016 the Convention between the Holy See and the Government of the Italian Republic on fiscal matters, signed on 1 April 2015, came into effect. On 23 November 2016 there entered into effect the Avenant between the Holy See and the French Republic, signed on the previous 25 July, to the diplomatic conventions of 14 May and 8 September 1828 and the Avenants of 4 May 1974, 21 January 1999 and 12 July 2005 regarding the Church and the Convent of Trinità dei Monte in Urbe. Then, on 15 September, a Memorandum of Interest was signed by the Secretariat of State and the Government of the United Arab Emirates on mutual exemption for entry visas for holders of diplomatic passports and special passports (official and service). Finally, on 19 September the Holy See, also in the name and on behalf of Vatican City State, adhered to the United Nations Convention against Corruption, of 31 October 2003.