Prime Minister Boris Johnson has acknowledged "turbulence" in the UK's relationship with France as the row over fishing rights escalates, reports BBC News.
After dozens of French boats were denied post-Brexit fishing licences for UK and Jersey waters, France threatened to block ports to British vessels.
But Mr Johnson told the BBC the things that united the UK and France were more important than their divisions.
The French president said the row was a test of the UK's global credibility.
France has said it will take "targeted measures" against the UK if the row over fishing licences is not resolved by Tuesday.
Brexit Minister David Frost said the government was "actively considering" launching a legal process against France under the Brexit agreement, as a result of the "threats" from France.
Lord Frost described language used by French Prime Minister Jean Castex as "clearly very troubling and very problematic" in the context of ongoing negotiations "trying to solve many highly sensitive issues, including on the Northern Ireland Protocol".
His comments followed the emergence of a letter by Mr Castex, seen by the BBC, which said the EU must demonstrate in this dispute that there was "more damage to leaving the EU than remaining there".
Writing on Twitter, Mr Frost said: "We will continue to talk constructively to try to resolve all the differences between us, and we urge the EU and France to step back from rhetoric and actions that make this more difficult."
Pressed on how the UK would respond to the threats as the G20 group of major economies met, Mr Johnson told the BBC: "We're going to get on and do the things that matter to both of us and make sure that we work together on tackling the big issues that face the world."
Referring to Mr Castex's letter, he acknowledged that "there's some turbulence in the relationship".
"If one of our partners decides to breach the Trade and Cooperation Agreement that we struck, that's a matter that we have to pursue," Mr Johnson said.