Ukraine's Orthodox Christian Church celebrated its first Christmas on Monday outside Russian control and President Petro Poroshenko said the document enshrining its newly gained independence had broken 'the last fetters tying us to Moscow'.

Hundreds of Ukrainians queued in the snow after the lavish two-hour liturgy at Kiev's St Sophia Cathedral to view the document, known as a 'Tomos', which was only handed to the head of the new Church Metropolitan Epifaniy on Sunday.

Many Orthodox Christians celebrate Christmas on January 7, not December 25, as they follow a different calendar.

Accompanied by Poroshenko, Epifaniy processed into the cathedral on Monday carrying the decree, a scrolled white parchment. White-robed clergy then unfurled it and placed it in front of the iconostasis, a richly decorated screen that separates the sanctuary from the nave in Orthodox churches.

'For the first time, we celebrate Christmas with an independent autocephalous church,' said Poroshenko after the service. 'It is the basis of our spiritual freedom, we broke the last fetters tying us to Moscow,' said the president, who faces a tough re-election battle this year.

Russia bitterly opposes the move to grant the Ukrainian Church autocephalous, or self-governing, status, comparing it to the Great Schism of 1054 that divided western and eastern Christianity.

The Russian Orthodox Church in Moscow has called the leaders of the Ukrainian Church charlatans and schismatics, and President Vladimir Putin has warned of possible bloodshed.

Despite the snowy weather, hundreds of people watched Monday's service on a big screen outside because there was not enough space in the packed cathedral to accommodate them.

'This is the most happy day in the life of every Ukrainian. And I understand that every soul desires to be here,' Oksana Pasenok, a university professor, told Reuters.

People formed a long queue after the service to see the decree, which will remain on public display.

'Today the words of those holy fathers who died for Ukraine, for our freedom, for our liberty, come true,' said Oleksandr Sydoruk, engineer, standing in the queue to see the document.

'Today, with this "Tomos", our Ukrainian Church and Ukraine revive. And this is a day of joy for all Ukrainian Orthodox believers.'

St Sophia Cathedral was built by the son of Prince Volodymyr, whose baptism in 988 led to the spread of Christianity across what are now Ukraine and Russia.

Russians trace the origins of their own nation to the Kievan state of that era.

The rupture in inter-church relations mirrors the collapse of political relations between Moscow and Kiev following Russia's annexation of Crimea in 2014 and its support for separatist rebels in eastern Ukraine.