He was reacting to Theresa May's combative speech on Wednesday in which she accused some in Brussels of "not wanting Britain to prosper".
Launching the Conservative Party's general election campaign after the dissolution of Parliament, she suggested leaks and threats had been "deliberately timed to affect the result of the general election."
Speaking on Thursday, Tajani said, “I met Mrs May two weeks ago in London and I said that it is not easy to see what is the UK’s goal. Even so, I said I am not pessimistic and believe there will be an agreement.”
The Italian deputy added, “We on the EU side are not seeking to influence the campaign in the UK. I just told her that we will defend the interests of millions of EU citizens in the UK and those British citizens living in Europe. There is no question of trying to influence the election campaign.
“This is not an attack on the UK but merely to say that being a non-member of the EU cannot be the same as being a member. In any case I do not think the British will be swayed by things they see in the press and the talks will not start until after the UK election, not before.”
Tajani, who was speaking at a news conference for the opening of the House of European History, also said that without an agreement on citizens’ rights the Parliament “will not be able to agree a deal with the UK.”
He also voiced full confidence in Michel Barnier, the EU’s chief negotiator, who he said “is the best possible negotiator and will do a good job. He has my full support.”
Barnier himself had been mildly critical of the UK’s Brexit position when he outlined the EU’s negotiating directives this week.
Further comment on May’s outburst came from Mairead McGuinness, Vice President of the European Parliament, who warned of the damage such "emotive, electioneering language" could do to the subsequent negotiations.
"The election that's happening in the UK will of course impact the current discussions in the UK, and probably here as well, but when all of this is over there will have to be a settling down and dealing with reality," she said.
Conservative MEP Daniel Hannan said that the Prime Minister was right to fire back after European Commission President Jean Claude Juncker said it was a "constructive meeting" then leaked a different account to a German newspaper.
After being "traduced in a foreign newspaper with the most grotesque version of events, I think she has every right to feel cross.”
SNP MEP Alyn Smith said, “This was a disgraceful intervention, deliberately trying to stir up anti Brussels feeling for a short term, possible, gain. Neither strong nor stable, ‘the rocks are out to get us’ shrieks the captain steering towards the rocks". Not in Scotland's name.”