"Both sides must implement what we agreed on," von der Leyen, European Commission president, said after meeting Johnson alongside Michel, the European Council president.
"There is complete EU unity on this," she said, adding that the deal had been agreed, signed and ratified by both Johnson's government and the bloc.
The G7 is trying to find a coherent response to the growing assertiveness of President Xi Jinping after China's spectacular economic and military rise over the past 40 years.
But unionists say it contravenes the 1998 peace deal and London has said the Protocol is unsustainable in its current form after supplies of everyday goods to Northern Ireland were disrupted.
"The European Council calls on the UK to respect the principle of non-discrimination among member states and the rights of EU citizens," said the draft, a copy of which was seen by Reuters.
The EU has already launched legal proceedings against Britain over a unilateral six-month delay to imposing customs controls on goods arriving in Northern Ireland from Britain.
London Mayot says he will leave no stone unturned to get the city back on its feet
Sadiq Khan had criticized Brexit and successive Conservative prime ministers, including his mayoral predecessor Boris Johnson, as well as for a feud with former US President Donald Trump
Victory there would boost Johnson, and heap pressure on Starmer, as he tries to reposition the party after the hard-left leadership of his predecessor Jeremy Corbyn.
8 On Friday, Britain authorised 41 ships equipped with Vessel Monitoring System (VMS) technology -- which allows ships to be located -- to fish in waters off the island of Jersey, which is a self-governing British Crown Dependency.
The UK had insisted it wanted to take back control of its waters while EU coastal states sought guarantees that their fleets could keep fishing in British waters.
Currently the treaty is provisionally applied, pending the European Parliament's adoption. British MPs ratified it the day it was signed, on December 30, 2020.