The prime minister promised during the general election campaign that he would not seek an extension to the transition period - persuading ¼°µ¿Æ÷ÀåÀÌ»ç Brexit Party leader Nigel Farage to stand down candidates in Tory seats.
Sam Lowe, from the Æ÷ÀåÀÌ»çºñ¿ë Centre for European Reform think tank, told BBC Radio 4's Today programme that Mr Johnson's move was "slightly performative" and its effect would be "largely domestic".
"It is a firmer deadline but of course there is still some flexibility," he said.
"The prospect of a no-deal is still there," Mr Lowe said. "The question is whether Boris Johnson wants a no-deal but the evidence of recent time suggests no he doesn't."
The amendments to the withdrawal agreement come after Mr Johnson carried out a limited reshuffle of his government on Monday.