By Dan Bilefsky and Shashank Bengali

BRUSSELS – By visiting Ukraine for a summit with President Volodymyr Zelenskyy, top European Union officials demonstrated continued support for Kyiv’s battle against Russia’s invasion. But Ukraine is likely to be frustrated in its greater objective: being admitted into the bloc’s economic and political partnership as an EU member state.

Here is what you need to know about Ukraine’s EU bid.

A speedy accession is unlikely

In June, the bloc formally granted Ukraine, along with Moldova, EU candidate status, the first step in a lengthy joining process that usually takes a decade or longer. Poland, for example, made a formal request to join the bloc in 1994 and was finally admitted in 2004.

To join, a country needs its candidacy to be unanimously approved by all EU member states, which now number 27. It must also make its political system, judiciary and economy compatible with the bloc by adopting the EU’s system of common law, as well as more than 80,000 pages of rules and regulations on everything from environmental standards to food hygiene rules.

One senior EU official explained that it can take as long as 18 months for the European Commission to evaluate a country’s application before it goes to member countries.

And while there are precedents for fast-tracking — Sweden and Finland managed to join the Union in a few years after applying — a speedy approach is rare.

Other countries are in line ahead of Ukraine

Several countries have been waiting for years to join the bloc, including Albania, Bosnia and Serbia, making it difficult for the EU to move faster on Ukraine.

Beyond that, the EU also has expansion fatigue after being buffeted by economic crises, Brexit and the pandemic, as well as the misbehaviour of rule-breaking member countries like Hungary.

The prospect of EU membership has spurred reform in other countries

The European Union’s ability to offer membership to a country has been one of its greatest foreign policy tools in the post-Cold War world. The prospect of joining motivated Bulgaria and Romania to tackle corruption and accelerated the arrest of war criminals in Croatia, Serbia and Montenegro.

In the past few days, Ukrainian authorities have conducted raids and fired officials in a stepped-up effort to illustrate a commitment to fighting corruption.

Ukraine has been ardent about forging closer links with Europe

Before Ukraine was made an official EU candidate, it signed an association agreement in 2014 in which it agreed to intensify economic and political ties with the bloc. A year earlier, hundreds of thousands of Ukrainians took to the streets to protest when the president at the time, Viktor Yanukovych, who leaned toward Russia, backtracked on signing an association agreement with the union.

Whatever the challenges for Ukraine’s EU hopes, Russia’s aggression has engendered an outpouring of solidarity in the bloc, drawing some of the toughest sanctions in its history. East and central European countries like Poland and the Baltics, which lived for decades behind the Iron Curtain and where memories of Russian subjugation run deep, have been among the most enthusiastic in backing Ukraine’s membership.

Most Europeans welcomed the EU’s eastward expansion in May 2004, when the bloc admitted 10 mostly former communist countries — including the Czech Republic, Hungary and Poland — because, among other reasons, it cemented the demise of the Soviet bloc, and helped spread economic and political liberalism across the continent.

Even though Ukraine’s EU membership process is likely to be gradual, the country’s attempt to forge closer ties the EU and with NATO — a defensive military alliance that shares many members with the bloc — underlines how President Vladimir Putin’s attempt to bring Ukraine back into Russia’s orbit by force appears to be having the opposite effect.