Kiev (AFP) - Mikheil Saakashvili, the former fiercely pro-Western leader of Georgia, has been appointed an aide to the Ukraine president to help the war-torn country on its path to reform, officials said.

In his new job as the head of the Advisory International Council of Reforms, the 47-year-old former president will help implement best practices and build global support for the ex-Soviet country.

"Mikheil will become a representative of Ukraine abroad and, simultaneously, a representative of the international community in Ukraine," President Petro Poroshenko said in a statement.

Saakashvili for his part said Ukrainians deserved a better future free of corruption and injustice.

"We will not win if we do not build a new Ukraine today and do not implement new reforms," he was quoted as saying in a statement.

A charismatic lawyer, Saakashvili rose to power in Georgia after the Rose Revolution that ousted the country’s former leader, ex-Soviet foreign minister Eduard Shevardnadze, in 2003.

During his decade in power he was praised for modernising reforms that brought Georgia back from the brink of economic collapse and tackled widespread corruption but drew criticism for the country’s defeat in a brief war with arch-foe Russia in 2008.

Saakashvili said Ukrainian officials had earlier suggested that he apply for a job of head of the Anti-Corruption Bureau, but he did not want to renounce his Georgian citizenship.

Ukraine has earlier installed several foreigners in top government posts.

Lithuania-born Aivaras Abromavicius was appointed economic development and trade minister while United States-born Natalia Jaresko became finance minister.

Alexander Kvitashvili, also from Georgia, was appointed health minister.

Ukraine, which has been battling against pro-Russian separatists in the east since April, is in dire economic straits.

Fitch on Friday downgraded Ukraine's credit rating a notch deeper in junk territory, citing an increased probability of default.