By Philip Pullella and Margarita Antidze

TBILISI (Reuters) - Pope Francis called for respect for international law and the sovereign rights of nations as he arrived in Georgia on Friday, an implicit criticism of Russia, which keeps troops in two breakaway areas of the ex-Soviet state.

But Francis measured his words carefully, in an apparent attempt not to hurt the Vatican's increasingly warm ties with the Kremlin-backed Russian Orthodox Church.

Georgia won independence in 1991 but the Kremlin's shadow still looms large. Russia, which fought a short war with Georgia in 2008, is one of the few countries that recognize the contested areas of Abkhazia and South Ossetia as independent states.

Speaking at the welcoming ceremony at the presidential palace, Francis, in a clear reference to the Georgian situation, said relations between states in the region "can never lay aside respect for the sovereign rights of every country within the framework of international law".

Georgian President Georgy Margvelashvili said there was a desire for all people to live in dignity.

"But this mission cannot be accomplished in the light of violations of the rights of civilians and the territory being occupied by a neighboring country," he told the pope.

While not specifically mentioning Abkhazia and South Ossetia, Francis supported the right of displaced people to "freely return to that land".

The government says about 300,000 people have been forced from their homes by the conflict over the disputed territories. Moscow has opposed U.N. resolutions backing their right of return.

"CREEPING OCCUPATION"

Georgia, which wants to join the European Union and NATO, has accused Russia of practicing "creeping occupation" by slowly moving fences delineating the breakaway areas from the rest of Georgia's territory.

"We are just 40 km (25 miles) away from barbed wire fences preventing civilian populations - neighbors, relatives, family members - from having contact with each other," the president said.

Less than one percent of Georgia's population of about 3.7 million are Catholic. The overwhelming majority belong to Orthodox Christianity, which broke with Rome in 1054.

Under Francis, who was elected in 2013, the Vatican has made a concerted effort to improve relations with Orthodox Christians in the hopes of an eventual reunion. Earlier this year, he held a historic meeting with Kirill, the patriarch of the Russian Orthodox Church.

The Georgian Orthodox Church is one of the more conservative in the Orthodox world. Some of its more hard-core members protested at the airport. They held signs reading: "Vatican is a spiritual aggressor" and "Pope, arch-heretic, you are not welcome in Orthodox Georgia".

But on Friday evening there was no sign of tension between the two Churches as Georgia's ailing, 83-year-old Orthodox leader, Patriarch Ilia II, warmly welcomed the pope.

Francis also visited a church of the country's Assyrian-Chaldean Christian community, where he prayed for victims of war in the Middle East, asking God to comfort those "wearied by bombing" and to "raise up Iraq and Syria from devastation"

(Reporting by Philip Pullella; Editing by Ralph Boulton)