Europe’s most powerful leaders have congratulated Moldova’s pro-western president, Maia Sandu, after she won a second term, cementing the country’s EU aspirations and dealing a setback to the Kremlin.

With nearly 98% of the vote counted in the second round of the presidential elections on Sunday, Sandu had 54% of the vote, ahead of Alexandr Stoianoglo, a Kremlin-friendly political newcomer, backed by the pro-Russia party of Socialists.

Moldovan authorities reported evidence of attempts to meddle in the electoral process before Sunday’s vote and during the first round of voting and a referendum on EU membership that was won by a wafer-thin margin two weeks earlier.

Allegations of Russian or pro-Russia interference, including cyber-attacks on polling stations, bussing in voters, vote-buying and intimidation, underscored the stakes for the small former Soviet republic that has pursued a decisively pro-western path under Sandu, seeking to join the EU.

The head of the European Commission, Ursula von der Leyen, congratulated Sandu, saying: “It takes a rare kind of strength to overcome the challenges you’ve faced in this election. I’m glad to continue working with you towards a European future for Moldova and its people.”

In a joint statement, the commission and the EU’s top diplomat, Josep Borrell, praised the Moldovan authorities “for the successful conduct of the election, despite unprecedented interference by Russia, including with vote-buying schemes and disinformation”, adding that “these hybrid attempts have sought to undermine the country’s democratic institutions and its EU path”.

The French president, Emmanuel Macron, said democracy had triumphed over all interference and manoeuvring: “France will continue to remain at the side of Moldova in her European path,” he wrote on X.

The German chancellor, Olaf Scholz, echoed this sentiment. “@sandumaiamd has steered the Republic of Moldova safely through difficult times and set the country on a European course. We stand by Moldova’s side,” he said.

Ukraine’s president, Volodymyr Zelenskyy, said his country was ready to support Moldova’s European choice. “Moldovans have made a clear choice – they chose a path toward economic growth and social stability. Only true security and a peaceful, united Europe can guarantee each person and every family the confidence to face tomorrow with hope and certainty.”

Moldova filed its application to join the EU in March 2022 only days after Ukraine announced its intention to become an EU member state, following Russia’s full-scale invasion. Both countries were granted EU candidate status in June 2022 in an accelerated process.

In the run-up to the first round of voting in the presidential elections, the commission proposed a €1.8bn (£1.5bn) growth plan for Moldova, with the aim of doubling the size of the Moldovan economy over the next 10 years. The plan links financial aid (grants and cheap loans) to reforms, but still has to be agreed by EU member states and the European parliament, a five- or six-month process.

Siegfried Mureșan, a Romanian MEP who will lead talks for the European parliament on the Moldova growth plan, promised the EU would pass the legislation as quickly as possible “so we can enable the necessary investments needed to help the country modernise and be prepared for EU accession”.

He described the result as “a victory for the citizens of the Republic of Moldova and a defeat for the Russian Federation”.

The Kremlin has denied interfering in the vote. “We resolutely reject any accusations that we are somehow interfering in this. We are not doing this,” the Kremlin spokesperson, Dmitry Peskov, said.

A senior Russian senator and an ally of President Vladimir Putin said on Monday that votes were “brought in” to help Sandu win. “You count the votes, you see how many the ‘right’ candidate is missing and bring in the required number of votes from foreign polling stations,” Andrei Klishas, a member of Russia’s Federation Council, said, referring to diaspora voting.

One EU leader conspicuous by his silence in the immediate aftermath of the vote was Viktor Orbán. The Hungarian prime minister angered EU officials last week when he flew to Georgia the day after parliamentary elections, having offered his congratulations to the pro-Russian ruling party before the final tally had been officially announced. In the first 12 hours after the results of Moldova’s election became clear, Orbán had not immediately commented to international media.

Poland’s prime minister, Donald Tusk, offered his congratulations in a message likely to be pointing to another presidential race that has also had allegations of Russian interference – the US.

“Despite Russia’s aggressive and massive interference in the Moldovan presidential elections, Maia Sandu most likely defeated Moscow’s favourite,” Tusk wrote on X, before the final election results were counted. “Let’s hope that this trend will continue in the coming days and months in other countries as well.”