European Union ambassadors were convening on Christmas Day to start assessing the massive free-trade deal the bloc struck with Britain on Thursday after nine months of negotiations. "EU member states will now start reviewing the 1,246 pages of the EU-UK agreement and continue with this daunting exercise during the next few days," tweeted EU German Presidency spokesman Sebastian Fischer as the meeting started. For the deal to enter into force, the EU's 27 countries will need to unanimously back the agreement, a prerequisite for its legal approval. A moment of "historical importance", an "important milestone", a "major step forward" — European leaders welcomed on Thursday the newly-unveiled post-Brexit deal with the UK. But most have also reiterated warnings that despite the deal, changes to the current relationship will come into force on Jan. 1. German Chancellor Angela Markel said she was "pleased" that an agreement had been reached, adding: "This is of historical importance." European Council President Charles Michel branded the deal "a major step forward". "#EU27 unity has been and will remain key," he added on Twitter. Preserving peace in Ireland and ensuring that no physical border between the British province in the north and the EU member state in the south is erected has been one of the thorniest issues for negotiators. Irish Taoiseach Micheal Martin said in a statement that "the agreement reached today is the least bad version of Brexit possible, given current circumstances." "I know that not everyone is happy with the Protocol, but I believe it is a good outcome for the people of Northern Ireland," he went on, because it enables smooth trade between the island's two entities and "avoids a return of a hard border" The deal will now need to be approved by the EU and UK parliaments as well as policymakers in all 27 member states. European Parliament President David Sassoli said in a statement that he welcomed the deal but flagged that "the last-minute nature of the agreement does not allow for proper parliamentary scrutiny by the European Parliament before the end of the year." "The Parliament is now ready to react responsibly in order to minimize disruption to citizens and business and prevent the chaos and negative consequences of a no-deal scenario. The Parliament will continue its work in the responsible committees and the full plenary before deciding whether to give consent in the new year," he added. The Commission said in a statement that the introduction of the trade agreement is "a matter of special urgency" and proposed applying the trade deal on a "provisional basis, for a limited period of time until Feb. 28, 2021." This, it said, would enable MEPs to exercise their "right of democratic scrutiny, in accordance with the Treaties." In the UK, Prime Minister Boris Johnson said he hoped to bring the deal in front of lawmakers on Dec. 30. Other political formations in the UK were less enthused. Scotland's First Minister Nicola Sturgeon reiterated that the UK's departure from the EU "is happening against Scotland's will". "There is no deal that will ever make up for what Brexit takes away from us. It's time to chart our own future as an independent, European nation," she added, once more, raising the threat of another independence bid. She also deplored the UK withdrawal from the Erasmus student exchange program as "cultural vandalism". Anneliese Dodds, from the main opposition Labour party, said before the announcement that a deal would lead to many businesses "breathing a sigh of relief" "Yet early indications suggest this thin deal will have a major negative impact on GDP. "With key industries subject to substantial barriers, these are not the promised ‘exact same benefits'," she added. Meanwhile, the EU is said to have approved exports of meat and dairy products from the UK, something the National Farmers Union (NFU) hailed in a statement. "Receiving third country listing status from the EU for our animal products is absolutely critical and will allow an export trade worth more than £3 billion to continue at the end of the transition period," said NFU President Minette Batters. "This means the UK has met all of the necessary animal health and biosecurity standards the EU requires for this trade and is a step forward in the government's preparations for the end of the transition period. "While this listing is good news, we must bear in mind that there will be significant friction for our exports to the EU from Jan. 1 and it's crucial the government minimizes this disruption as much as possible in the time remaining," she added. — Euronews