Russia and Ukraine have agreed to restore a 2020 ceasefire deal in eastern Ukraine, prompting a top official in Kyiv to say that the coming holidays "should be peaceful".

Ukrainian presidential chief of staff Andriy Yermak hailed the deal brokered by Europe's OSCE security organisation as a step towards de-escalation.

The agreement coincides with heightened tensions in the region.

Ukraine and the West say Russia has sent 100,000 troops near the border.

Earlier this week Russian President Vladimir Putin threatened "adequate military-technical response measures" if what he called the West's aggressive line continued. However, he said on Thursday it was not his preferred choice and expressed hope for talks in Geneva with the US next month.

Russian officials deny any plans for an invasion, however the defence ministry in Moscow said it was carrying out military exercises in the area on Thursday and Friday. Germany has expressed alarm at Russia's troop movements and said dialogue was "now essential to try to defuse a major crisis".

President Putin has demanded guarantees that Nato will abandon military activity in Eastern Europe and not allow Ukraine to join the Western defensive alliance. During his annual end-of-year press conference he accused Nato of cheating Russia with five waves of expansion.

Russia has reportedly sent the US proposed dates for talks next month, according to reports from Moscow. The ball was now in the West's court, Mr Putin told journalists.

Nato Secretary-General Jens Stoltenberg said this week he also hoped for talks with Russia early next year but was adamant that Ukraine's membership of the alliance was up to Nato and Kyiv: "Any dialogue with Russia has of course to respect the core principles which European security has been based on."

For seven years Ukrainian forces have been at war with Russian-backed separatists who seized large areas of eastern Ukraine known as the Donbas.

More than 14,000 people have been killed in that time. Although combat ended in 2015, clashes continued to break out and a July 2020 ceasefire was meant to bring the violence to an end.

Ceasefire violations have surged of late, and defence officials in Kyiv accuse Russia of sending 122,000 troops to within 200km (125 miles) of Ukraine's borders. A further 143,500 are stationed within 400km, they allege.

Late on Wednesday the two countries along with the Russian-backed rebels agreed with the Organisation for Security and Cooperation in Europe to reinforce the truce. The OSCE aims to prevent conflict and manage crises and has a monitoring mission in eastern Ukraine.

OSCE Ambassador Mikko Kinnunen praised the deal as particularly important as his organisation's monitors have recorded five times more ceasefire violations this month than in December last year.

"This is a step towards de-escalation," Mr Yermak said on Facebook. "We hope that this time the ceasefire will be lasting and will help save lives of Ukrainian defenders and civilians."

On Thursday Ukraine's joint forces headquarters said no breaches by the separatists had been reported in the past 24 hours.