BRASïLIA (AFP) - Ukraine's leader has accepted an invitation to attend Sunday's World Cup final, with Russian President Vladimir Putin also among the spectators, amid a crisis between their countries, Brazilian officials said.

"The president of Ukraine (Petro Poroshenko) confirmed Friday that he will go to the final," a Brazilian presidency spokesman told AFP on Saturday.

A foreign ministry spokesman said the Ukrainian and Russian leaders would attend a lunch offered by President Dilma Rousseff before the Germany-Argentina final at Rio de Janeiro's Maracana Stadium.

Mr Putin, whose country will host the 2018 World Cup, had confirmed his attendance weeks ago. He will also attend a summit of the BRICS group of emerging powers on Tuesday.

German Chancellor Angela Merkel, who is also attending the game, will meet with Mr Putin in Rio.

In late June, the Russian and Ukrainian leaders held telephone talks with Ms Merkel and French President Francois Hollande in a bid to secure a truce between Kiev and pro-Russia separatists in the east of Ukraine.

On Saturday, panicked Ukrainians flooded highways and packed trains leading out of the main remaining rebel stronghold, fearing a reprisal assault by government forces after they lost 30 servicemen to defiant militants.