BUDAPEST (Reuters) - Ukraine cannot win the war with Russia on the battlefield, Hungarian Prime Minister Viktor Orban said on Tuesday, adding dialogue and a ceasefire were needed to save lives.

Earlier, Hungary's finance minister said Budapest would hold up a final deal on a $50 billion G7 loan to Ukraine until after the U.S. presidential election by delaying its decision on the timing of the renewal of EU sanctions against Russia.

Speaking at a briefing in Strasbourg, Orban said that U.S. Republican presidential candidate Donald Trump, if elected, would not wait until his inauguration but would start working for peace in Ukraine right after the Nov. 5 election, adding that European leaders would have to react to that.

Orban, who has long endorsed Trump, also said that both direct and indirect communications were needed between the warring parties and it was a part of international politics that a third party mediates between them.

"We don't want to block anything, we just want to convince European leaders to change their strategy (on Ukraine) because the current strategy does not work," Orban said.

Days after Hungary took over the EU's rotating presidency in July, Orban set out on a self-styled peace mission which included a visit to Moscow and Kyiv and also Trump, and triggered a backlash from European leaders.

Orban said his country wanted a normal economic relationship with Russia in areas not affected by sanctions. Hungary relies heavily on Russian crude and gas imports, and Russia's Rosatom is also building a nuclear power plant in Hungary.

"We are transparent, we do what we say. And we think that in the areas where there are no sanctions between the EU and Russia naturally we would like to have normal economic relations with Russia," Orban said, accusing some Western peers of "hypocrisy", citing how much oil and gas they had bought from Russia. He did not name the countries.

Orban's press conference was briefly interrupted by a politician from the opposition Democratic Coalition (DK), who ran into the room shouting and accusing Orban of "betraying" his country, selling it out to Russia and China. He was escorted out by security.

(Reporting by Krisztina Than and Anita Komuves; Editing by Mark Potter)