"My government ends today," said Italian Prime Minister Matteo Renzi just after midnight on Monday, in a televised address from the Palazzo Chigi. "I take full responsibility for this defeat."

Renzi said he could not refute the "extraordinarily clear" results of Sunday's referendum on constitutional reforms, and called on his rivals to provide clear proposals for ending the continuous cycle of political deadlock in Rome. He offered his condolences to those in his "Yes" camp, congratulating them on a hard-fought campaign.

"Good luck to us all," said the prime minister of two-and-a-half years, saying he would give his letter of resignation to President Sergio Mattarella later on Monday.

Europe calls for fast solution

German Chancellor Angela Merkel said she was saddened by Premier Matteo Renzi's defeat in the Italian constitutional referendum.

"I am sad that the referendum in Italy didn't turn out the way the premier wanted, because I have always supported his course of reform."

However, she said she believed that Europe as a whole was on the right track.

"From my point of view, we will continue our work in Europe and we have set the right priorities."

Following Renzi's referendum defeat, German Foreign Minister Frank-Walter Steinmeier said he hoped the government crisis in Italy would resolve quickly.

German Finance Minister Wolfgang Schäuble, meanwhile, urged Italy to continue with Renzi's economic reforms during a call with his Italian counterpart on Monday.

France and Luxembourg, on the other hand, viewed the result as a domestic issue that did not signify a defeat for Europe. French Finance Minister Michel Sapin said the result poses no systemic risk to the euro zone.

Likewise, Luxembourg's foreign minister, Jean Asselborn, called the referendum a "domestic political argument," in comments to news agency DPA. He said the issue should not be extended to the European level, but added that a drawn-out government crisis would be bad for the euro.

'No' constitutional change in Rome

With all votes counted, results showed 59 percent of Italians voting against Renzi's proposed reforms, with just under 41 percent in favor, the Interior Ministry said on Monday.

Turnout for the election was high, with 65 percent of the 47 million registered voters in Italy casting ballots.

At stake were a number of governmental changes pushed by Renzi and his center-left Democratic Party (PD), which was hoping to rein in an unwieldy parliament by cutting the number of representatives in the upper-house Senate, getting rid of unproductive constitutional bodies and centralizing more power with the executive.

Renzi beset on all sides

Renzi had faced an uphill battle from the start. By vowing to step down in the case of a "No" victory, he conflated constitutional change with support for himself and his party. In addition, his opposition came from all sides: Former Prime Minister Silvio Berlusconi's right-leaning Forza Italia Party, populists Lega Nord and the 5-Star Movement (M5S), and even some members of his own PD were against the move.

Ahead of the polls, many analysts voiced their concern over the possible instability a "No" vote could usher in, and what effect that might have on global markets.

A further concern among those familiar with Italian domestic politics was the possible rise of M5S, a nebulous left-leaning anti-establishment party that has little governing experience and no clear political agenda. Despite ostensibly being leftist, M5S spokesman Beppe Grillo welcomed last month's election of Donald Trump, saying that the people were beginning to show their discontent with the status quo.

'Our revolution will not stop'

M5S was quick to hail the referendum results, with Grillo writing on his popular blog: "This vote has two significant consequences. First: Farewell Renzi. Second: Italians must be called to vote in a general election as soon as possible."

Virginia Raggi, the mayor of Rome and Italy's most visible M5S politician, wrote on Twitter that "the Italians have won. Now we rebuild our country. Our revolution will not stop, in Rome and Italy."

France's far-right National Front leader, Marine Le Pen, also welcomed the news as part of her euroskeptic agenda, saying: "The Italians have rejected the EU and Renzi. This thirst for the liberty of nations and protection must be listened to!" 

Le Pen has her eye on the French presidency as general elections approach in 2017, hoping to capitalize on the wave of populist and anti-establishment upsets that began with Brexit and Trump.

rs, es/kms (AP, AFP, dpa, Reuters)