The UK is set to leave the EU by the end of January and then start negotiating its long-term relationship with the bloc, according to Boris Johnson's Brexit bill. The two sides then have until December 31 to hammer out a permanent accord, and the UK prime minister has ruled out any extension to this deadline. If the negotiators fail to agree, however, the UK could once again face a no-deal scenario.

"I am very worried given the little time we have," European Commission leader Ursula von der Leyen said in an interview published on Friday.

London and Brussels should "seriously consider whether the negotiations are feasible" with the current deadline, she told French newspaper Les Echos.

Ticking clock never stops

Originally, the Brexit deal allowed the option to ask for one or two years of extra time. Any such requests are to be filed before June 30, 2020. Talking to the paper, von der Leyen also said it would be "reasonable to review things in the middle of the year" and consider an extension.

Read more: What happens with Brexit after Boris Johnson's victory? 

However, Prime Minister Johnson had amended the deal before presenting it to the UK Parliament, aiming to make it illegal to extend the talks past the end of 2020. Johnson commands a large majority in the assembly, and the amended version of the bill is set to become law once the parliamentary procedure is complete.

It remains to be seen if Johnson will change his mind before June 30. The UK prime minister has already been forced to go back on one of his earlier central pledges, namely that the UK would leave the EU in October 2019, "no ifs or buts." With the comfortable majority his Conservative Party won in December's election, arranging an extension via Parliament would not prove difficult for Johnson, should he elect to do so after all.

'The Brits were very reserved'

Germany's Von der Leyen also said that the UK's withdrawal would not harm the EU's security or adversely affect its foreign policy.

"Unlike in other areas, the Brits were very reserved when it comes to joint security and blocked some steps forward within the EU," she told Germany's Der Spiegel magazine.

For this reason, the EU's initiatives to reinforce defense cooperation could only start after the Brexit referendum, the politician added.

Even so, London and Brussels "are now striving for close cooperation" on security and defense, according to Von der Leyen, who until recently served as Germany's defense minister.

dj/msh (Reuters, AP, AFP, dpa)

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