Breton said an increase in prices for second generation vaccines could be justified by the extra research required and potential changes to industrial equipment.
The goal is to find a way back to the accord known by its acronym JCPOA, which former US president Donald Trump walked away from and which his successor Joe Biden wants to revive.
Prime Minister Imran Khan chaired a meeting of his senior cabinet members and close aides on Monday, to discuss the resolution passed by the European Parliament, which called for a review of their trade relations with Pakistan.
The European Parliament's resolution is linked with Pakistan's controversial blasphemy laws, and could potentially end Pakistan's eligibility for the Generalised Scheme of Preferences (GSP) trading status.
"The Russian ambassador has been summoned, he should be received in the afternoon by the secretary general of the European Commission and of the European External Action Service, where we will convey him strong condemnation and objection," an EU spokesman told a news briefing.