He will replace Vaidotas Verba as Lithuania's permanent representative to the Kingdom of the Netherlands and the Organization for the Prohibition of Chemical Weapons.
The Presidential Office calls Semaška's appointment "a normal diplomatic practice" when diplomats are rotated every 3-4 years.
Semaška has been adviser to President Dalia Grybauskaitė since July 2009.
In Lithuania, ambassadors are appointed and dismissed by the president upon the nomination of the government and the assent of the Seimas Committee on Foreign Affairs.
