Péter Magyar has said he has already spoken to 10 European leaders, a day after his landslide victory brought an end to Viktor Orbán's 16-year continuous rule in Hungary.
But he said he would not be calling Vladimir Putin, a close partner of Orbán, even though he would speak to him if the Russian leader rang.
If Vladimir Putin calls I'll pick up the phone, he told reporters during a three-hour marathon press conference to mark his Tisza party's election success on Sunday.
I don't think it'll happen, he stressed, but if we did talk I'd tell him to please, after four years, put an end to the killing and end this war.
Moscow has said it respects Magyar's victory and expects to retain pragmatic relations with Budapest.
Magyar told journalists that he would not be phoning Trump either, but if Trump phoned him, he would say he was glad as they were strong allies in NATO, and invite him to attend the 70th anniversary of the Hungarian uprising against Soviet occupation next October.
Latest preliminary results give Tisza 136 seats, down from an earlier figure of 138 but still a comfortable super majority of two-thirds of the seats in parliament, enabling the party to change the constitution. Magyar said some 400,000 votes had yet to be counted and he was optimistic his party would gain some of the remaining seats.
The war made no sense from a Russian perspective too, he said, as tens of thousands of Russians have lost their lives, and tens or even hundreds of thousands of Russian families have been destroyed including Russian-speaking people living in Ukraine.
