A member of the Bavarian Christian Social Union (CSU) who has been MEP since 2004, Weber will attend the SDS party convention in Celje on Friday.
He will also meet the heads of New Slovenia (NSi) and the People's Party (SLS), Matej Tonin and Marko Zidanšek. "They all have the support of their European political family, the EPP family," Weber pointed out.
Five of the eight Slovenian MEPs are members of the EPP - three from the ranks of the SDS and one each from the NSi and SLS.
Asked whether the Slovenian centre-right parties could repeat the same result at next year's election to the European Parliament, Weber said he would not speculate on this, but he stressed that the EPP had a good programme, focussing on security and the preservation of European identity.
According to Weber, the programme will be presented at the SDS convention on Friday, which will also feature Hungarian Prime Minister Viktor Orban, whose party is a member of the EPP.
While the EPP does not support Turkey's EU membership, it "fully supports the European perspective for Western Balkan countries", which however must first meet all the obligations and criteria and thus win the trust of EU citizens reserved about the enlargement process, Weber said.
He believes more people in the EU would support enlargement if the future borders of the EU were clearly defined; enlargement should not be presented as an endless process.
Weber also commented on the Slovenian-Croatian border arbitration award and Brussels's inaction over Croatia's refusal to implement the decision, which many people in Slovenia associate with the "EPP alliance" between European Commission President Jean-Claude Juncker and Croatian Prime Minister Andrej Plenković.
Asked to comment on whether the Commission was neglecting its role of guardian of the rule of law because of this alliance, Weber said there was no "party political background".
He said that everyone in Europe was hoping for a positive outcome and solution to this long-term problem and that Juncker had been clear in saying that the arbitration award must be respected. But at the end of the day, the two member states should be capable of solving such a problem, he said.
Asked about the impact of controversial figures like Orban or Janez Janša, the leader of the SDS, on the EPP's chances in the next election, he said that the EPP had supported Orban before the election but that they had different views on certain issues, for example on the Central European University.
But Weber pointed out that they had problems with other members as well and that issues were being discussed very openly. "There is light and also shadow in the relationships", he said.
"My main message is that it is much better to talk to each other in the European Union, to find solutions than to accuse each other."
As for Janša, he said that the EPP supported all its parties and party leaders. "I think our approach is a good one for Slovenia and for Europe," he stressed.