"We are not satisfied with the pace of the ratification process, 17 countries still need to do that. Today I will ask for the assistance to step up the ratification. I think that we have deserved that," said Karamarko who will participate in the EPP meeting for the first time since his recent election as the HDZ leader.

Asked to comment on Slovenian Foreign Minister Karl Erjavec's statement in the context of the issue of the Ljubljanska Banka and its clients in Croatia, that the ratification of Croatia's EU treaty would require a two-third majority in the Slovenian parliament, Karamarko said that one should be "wise and cool-headed".

"Anyway, we should be wise and cool-headed as we simply must have the accession treaty ratified, we must enter the EU on 1 July next year. We will certainly conduct appropriate talks with our counterparts in Slovenia about that. I know that it is a sensitive issue for them, and we will also stand on our principles in some matters and I think that we will find a solution," Karamarko told reporters.

He said that during his stay in Brussels he would hold several bilateral meetings and would possibly meet Slovenian Prime Minister Janez Jansa.

Slovakia was first to ratify Croatia's Accession Treaty on 1 February. Croatia's Treaty of Accession with the bloc has also been ratified by Hungary, Bulgaria, Italy, Malta, Latvia, Cyprus, Lithuania and the Czech Republic. The Romanian parliament on Tuesday ratified Croatia's EU, with the unanimous decision supported by 378 votes. The decision is now expected to be upheld by Romanian President Traian Basescu. On the same day, Czech President Vaclav Klaus signed the ratification document on Croatia's admission in the European Union and thus completed the ratification of Croatia's EU Accession Treaty in the Czech Republic.

On Wednesday, the Austrian parliament's committee on the constitution greenlighted the ratification of the treaty, thus paving the way for voting in the National Assembly next week and a possible ratification in July.