Speaking in Strasbourg on Tuesday, he said, "I believe we are reinventing ourselves and our citizens believe that an EU is better than no EU."
He cautioned, "But to deal with the many serious problems we still face we have to ensure we can protect the major interests of the EU. This includes defending the state of health of democracy in Europe, particularly in Hungary and Poland. Defending European values in these countries is more than just about money.
"I hope we can convince Hungarian Prime Minister Viktor Orbán and others that this is fundamental. I hope diplomacy works in this case but, if not, sanctions against Hungary will be necessary."
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With the issue of Turkey and alleged human rights abuses back on this week's agenda, Pittella also said again that his group was in favour of suspending accession talks with Turkey.
On Turkey, Ska Keller, the joint leader of the Greens/EFA group, said, "We need to recall that 50 per cent of Turks voted against President Recep Tayyip Erdoğan's constitutional changes and the Turkish people are looking towards the EU for our support on this and other issues."
The Greens, said the German MEP, have put the so called dieselgate scandal back on the agenda in parliament this week, "because this is not a single country issue, but one which affects all member states. It high time that people who bought diesel cars get a software update on their vehicles.
"We also need improved European inspection of such cars and the creation of a European authority in order to avoid such problems in future," said Keller, also speaking in Strasbourg on Tuesday.
At the start of this week's plenary on Monday, Parliament President Antonio Tajani commemorated those who have died in recent terrorist attacks and natural disasters.
At the opening of the session in Strasbourg he condemned acts of "inhuman violence" and expressed solidarity with the victims and their families in Barcelona, Cambrils and Turku.
The Italian said Parliament also stands with non-European countries which have suffered through terrorist attacks.
Tajani said, "Once again we are obliged to recall innocent victims of the murderous fury of terrorism."
On the anniversary of the attack on the Twin Towers, "each attack boosts our determination to fight terrorism and our hope in a better world. We do not intend to bow our heads in the face of terrorism", he noted.
The plenary held a minute of silence in memory of the victims of terrorist attacks and recent natural disasters.