UBS has been taking a conservative approach in dealing with fast-evolving sanctions imposed against Russian businesses and individuals over the invasion of Ukraine, Chief Executive Ralph Hamers said on Wednesday, saying all Russians were effectively "semi-sanctioned."

"We are working with our clients, including our Russian clients, to see how to manage their business and derisk their own situation," Hamers said. "I can't give a further update on the number of sanctioned clients, because it literally changes every day," he told the Morgan Stanley European Financials Conference, referring to a barrage of measures imposed by the United States, European Union, Britain and Switzerland since Russia invaded Ukraine.

"New lists come out every night, and we just go through the list and we match it against [our client relationships]. But, in principle, every Russian, every person with a Russian passport, is semi-sanctioned...in the UK, EU and Switzerland."