"Allow me to express my congratulations and best wishes on the occasion of your inauguration as President of the United States of America," Orbán wrote in the letter posted online by the government's international spokesman Zoltán Kovács.

"I firmly believe that the past four years have proved that the friendly and mutually beneficial cooperation between the USA and Hungary hold a great potential in many areas. It is my pleasure that this space of time has opened up new horizons in our bilateral relations in the fields of security, energy policy, and economy," he said.

"I can assure you that the Hungarian Government remains fully committed to further fostering Hungarian-U.S. relations on the basis of mutual respect and goodwill, building on our alliance in NATO, on our commitment to counter terrorism and on our common aspiration in securing alternative energy sources for Central Europe," he added.

"I wish you much success and good health in carrying out your highly responsible duties," Orbán wrote in closing.