A leading Swiss nongovernmental group on Monday called out Switzerland as a “safe haven” for Russian oligarchs and as a trading hub for Russian oil, grain and coal.

Public Eye called on the Swiss executive branch to “use all levers at its disposal to stop the financing of this inhuman aggression,” a reference to Russian President Vladimir Putin’s war in Ukraine that has killed untold thousands of people, driven millions from their homes and rippled through world economy by driving up food and fuel prices.

It spoke out on the day that the Swiss president was due to host a conference on Ukraine’s eventual recovery from Russia’s war involving government officials, advocacy groups and U.N. institutions.

Ignazio Cassis was hosting leaders, including Ukrainian President Volodymyr Zelenskyy by video message, at the Ukraine Recovery Conference in the bucolic lakeside town of Lugano. Swiss diplomats say the meeting aims try to map out a way forward for the world to help the war-battered country to recover and rebuild when Russia’s war ends one day.

Cassis was set to welcome Ukrainian Prime Minister Denys Shmyhal, leading a delegation of scores of Ukrainian ministers, lawmakers and others.

Public Eye said that “as a safe haven for oligarchs close to the Kremlin and as a trading hub for Russian oil, grain and coal, Switzerland bears a big political responsibility.”

It said Switzerland has been over the years a “popular refuge” for Russian business magnates to park their assets. The group said firms use Switzerland as an “unregulated commodity trading hub” and exploit a lack of transparency about financial dealings in the country.

There was no immediate response from the Swiss government.

The group welcomed Switzerland’s “humanitarian engagement” for Ukraine through the conference but called on the government to strictly implement international sanctions on Russian elites and their government, and better regulate its trading hub.

Switzerland is a major international financial center and its government has traditionally touted Swiss “neutrality” — which is enshrined into law — and Switzerland’s role as an intermediary between hostile countries and as a host of many international and U.N. institutions.

The Swiss Bankers Association has estimated that the assets of Russian clients deposited in Switzerland’s banks total 150-200 billion Swiss francs (about $155-$210 billion), making the country a key repository of Russian money abroad.

Swiss diplomats say hundreds of envoys from government, advocacy groups, the private sector, academia and U.N. organizations are expected for the Lugano gathering, which builds upon a multi-year, multi-country discussion about reform in Ukraine — even before the war began. The diplomats say the conference is the first to bring disparate groups together to unite to address Ukraine’s needs now.

Other top attendees expected to attend are European Commission President Ursula von der Leyen and British Foreign Secretary Liz Truss. More than half a dozen heads of state and more than a dozen government ministers are expected to take part, as well as heads of about a half-dozen international organizations, AP reports.