Boris Johnson has met Emmanuel Macron in Paris for Brexit talks, with the French president saying the UK's vote to quit the EU must be respected.
But he added that the Ireland-Northern Ireland backstop plan was "indispensable" to preserving political stability and the single market.
The backstop, opposed by Johnson, aims to prevent a hard border on the island of Ireland after Brexit.
Johnson said that with "energy and creativity we can find a way forward".
On Wednesday, German Chancellor Angela Merkel said the onus was on the UK to find a workable plan.
UK Prime Minister Johnson insists the backstop must be ditched if a no-deal exit from the EU on 31 October is to be avoided.