I have highly appreciated the work by Ivo Sanader as the prime minister who was steering the country towards European integration. The country is on the road towards the European Union membership. It has already become a NATO member. I thank Ivo Sanader for his commitment to European integration and to our good cooperation for years, Barroso said in a statement after Sanader announced earlier today he was withdrawing from the government and party duties.
Enlargement Commissioner Olli Rehn also said he appreciated Sanader's work although they sometimes discussed difficult topics.
His leadership and commitment to European integration processes has been useful to progress we have made, Rehn said.
He declined to comment on consequences of Sanader's resignation for effort to solve the Croatian-Slovenian border dispute which brought Croatia's EU accession negotiations to a standstill.
In Stockholm, Swedish Foreign Minister Carl Bildt said that he respected Sanader's decision.
"There comes a time in life when you want to do other things, and I have respect for his decision," Bildt was quoted by the German Press Agency (dpa) as saying.
Bildt said Sanader "will be missed," adding "he's been a very historically important voice for European integration and cooperation in his own country and in the region, as well as for reconciliation in a somewhat challenging part of Europe," according to the dpa.
Asked if Sanader's resignation would possibly impact the border dispute with EU member Slovenia that has blocked Croatia's EU entry, Bildt told dpa that he did not think that it would have any effect on that issue.
The head of the European People's Party caucus in the European Parliament, Jospeh Daul said he regretted Sanader's withdrawal.
I am personally sorry to hear that Sanader is leaving as I have witnessed over recent years the country's transformation under his leadership, Daul said.
German MEP Bernd Posselt, an official of the German Christian Social Union, blamed the European Union and its policy towards Croatia for Sanader's resignation.
Expressing regret at Sanader's decision, Posselt said that hypocrisy of the European Council and Commission forced Sanader whom he described as a great European to resign.
Posselt said that Rehn and the Swedish Presidency of the EU made a mistake when declaring the Croatian-Slovenian border dispute as a bilateral issue and thus causing a crisis in Croatia which he labelled as a country important for the stability of the entire continent.
Deputies of the Austrian People's Party (OeVP) in the European Parliament Ernst Strasser and Othmar Karas also expressed regret at the news about Sanader's resignation.
Sanader has brought Croatia on the threshold of EU membership, Strasser and Karas said in a joint statement for the media, describing Sanader as a great friend of Austria and man who is a driving force for Croatia's reforms,
Karas expressed optimism that Jadranka Kosor, Sanader's likeliest successor, would continue with successful cooperation in the EU and the EPP.
The media in the United States also carried reports about Sanader's resignations.
The Bloomberg news agency said "Croatian Prime Minister Ivo Sanader resigned for personal reasons, handing the reins of government to his deputy as the Balkan nation heads for a recession and its bid to join the European Union is stalled."
"Croatian Prime Minister Ivo Sanader unexpectedly resigned on Wednesday, saying he has decided to withdraw from politics after 20 years," the Wall Street Journal said on its web site.
"Mr. Sanader has been Croatia's prime minister since 2003 and won a second term in November 2007. He said he would recommend to President Stipe Mesic to appoint the deputy prime minister, Jadranka Kosor, to replace him," it said adding that "If Mr. Mesic accepts that, parliament will have to approve Mr. Kosor within 30 days. If that fails, new elections are called. Mr. Kosor ran unsuccessfully for president in 2005."
According to the paper Sanader insisted that "the growing economic crisis and Croatia's deadlocked membership negotiations with the European Union didn't affect his decision."
"I never ran away from problems and challenges," Sanader was quoted as saying adding that his successors "will find a solution" for current problems too.
The paper added that Sanader transformed the Croatian Democratic Union -- "once a bastion of nationalism in the Balkans -- into a Western-style conservative party."
The British BBC also pointed out that Sanader's resignation was unexpected.
The Canadian CTV aired the news about Sanader.