Budapest (dpa) - Hungarian Foreign Minister Peter Szijjarto travelled to Russia on Monday for the second time in six weeks.
The politician was taking part in the nuclear technology fair Atomexpo in the city of Sochi on the Black Sea, the Foreign Ministry in Budapest said.
Szijjarto visited an energy policy forum in Moscow last month.
Hungary's Prime Minister Viktor Orban has maintained good relations with Moscow since the Russian invasion of Ukraine in February.
Budapest supported the EU sanctions against Russia, but obtained an exemption from the embargo on Russian oil imports.
In September, Szijjarto was the only foreign minister from an EU country to meet Russian Minister Sergei Lavrov on the fringes of the UN General Assembly.
Szijjarto travelled to the nuclear exhibition in Sochi in connection with the construction of two new reactor units for the Paks nuclear power plant in Hungary by Russia's Rosatom.
"I sincerely hope that not a single European country will prevent this investment," Szijjarto said in Sochi, according to the Foreign Ministry.
Energy security is "nowadays a matter of national security, even sovereignty," he was cited as saying.