[3] Currently Lajčák is the EU Special Representative for the Belgrade-Pristina Dialogue and other Western Balkan regional issues, a position he assumed on 2 April 2020.

[15] Apart from his native Slovak, Lajčák is fluent in English, German, Russian, French and the South Slavic languages, including Bulgarian.

[17] His international engagements started in 1999 when he served as the Executive Assistant to the United Nations Secretary–General ́s Special Envoy for the Balkans, Eduard Kukan (until 2001).

[18] In 2005 the EU diplomacy chief Javier Solana called Lajčák to supervise the 2006 Montenegrin independence referendum, which was approved with a 55.5% of favourable votes.

During his tenure, BiH signed the Stabilization and Association Agreement with the EU, the most remarkable integration success of the country for many years to come.

Lajčák acted in 2007–09 in line with a moderately strong role of the OHR (using Bonn powers more than Schwarz-Schilling but less than Paddy Ashdown); critics of the international supervision of Bosnia and Herzegovina, including David Chandler, pointed to his "authoritarian stance" as responsible for creating a further crisis by trying to impose major institutional change and alter the Dayton peace agreement framework without domestic ownership or legitimacy.

[26] Lajčák is deemed to have achieved results on the ground but at the price of endangering the credibility of EU conditionality by accepting merely cosmetic legal changes.

Lajčák did resort to the use of the Bonn Powers in the crisis related to the 2007 Law on the Council of Ministers, which caused a showdown with Milorad Dodik’s SNSD.

[32] From December 2010 to April 2012 Lajčák served as managing director for Europe and Central Asia in the EU's External Action Service.

[22] After the 2014 Bosnian general election, he encouraged Dodik's SNSD party to enter the government coalition, despite having lost the Presidency seat, claiming that "new authorities must have legitimacy.

Lajčák later explained that Slovakia wanted Belgrade and Pristina to interpret it as a message, that the international community expects parties to submit such proposals on the basis of mutual agreement and consent.

[40] Since 2019, Lajčák has been serving on the Transatlantic Task Force of the German Marshall Fund and the Bundeskanzler-Helmut-Schmidt-Stiftung (BKHS), co-chaired by Karen Donfried and Wolfgang Ischinger.

[41] Between the EU-facilitated 5 August political agreement and the December breakthrough on a new SNSD-led government, on 27 Oct 2019, Lajčák invited both Milorad Dodik and Dragan Čović to Bratislava for "international mediation" which paved the way for BiH adopting its ANP with NATO.

[44] In his speech presenting the priorities for the Slovak Presidency Lajčák said "Today, we call the EU our home, the euro our currency and Schengen our area.

"[45] In November 2016, following revelations by a whistleblower, Transparency International Slovakia accused Lajčák of dubious procurement contracts during the Slovak EU Council Presidency.

His 12-months mandate includes the tasks to achieve comprehensive normalization of the relations between Serbia and Kosovo, improve good neighborly relations and reconciliation between partners in the Western Balkans, helping them overcome the legacy of the past, and contribute to the consistency and effectiveness of EU action in the Western Balkans.