Orban, who was formally endorsed by parliament as prime minister for a second consecutive term after last month's landslide election win, said ethnic Hungarians supported his policies to unite the nation "above the borders".
His previous government granted ethnic Hungarians in neighbouring countries citizenship shortly after it took office in 2010, as part of his efforts to restore a battered sense of national pride.
Orban, a 50-year-old former dissident against Communist rule, has also clashed repeatedly with the European Union over his go-it-alone policies in the past four years.
"We regard the Hungarian issue a European issue," Orban said in his first speech to parliament since his reelection.