Switzerland’s government has reported 6.3 billion Swiss francs ($6.33 billion) in Russian assets frozen within sanctions over the war in Ukraine. This is a decline from the beginning of last month, as around 3.4 billion francs in provisionally blocked assets were released, Reuters reports.

This figure is a fall of some 7.5 billion Swiss francs in funds that were reported frozen by the government in the first week of April. According to government official, Erwin Bollinger there was a lesser amount of funds – 2.2 billion francs - newly frozen, than those released.

"We can't freeze funds if we do not have sufficient grounds," said Bollinger, a senior official at the State Secretariat for Economic Affairs (SECO) agency.

Switzerland has been faced with increasing pressure to identify and freeze assets more rapidly of sanctioned Russians, the Reuters news agency reports.

The country was named "a leading enabler of Russian dictator Vladimir Putin and his cronies,” who used "Swiss secrecy laws to hide and protect the proceeds of their crimes,” said the U.S. Helsinki Commission, a government-funded independent commission focusing on security, cooperation and human rights in Europe.

However, the government has rebuffed the accusations "in the strongest possible terms", while President Ignazio Cassis asked the U.S. government to "correct this misleading impression immediately" during a call with U.S. Secretary of State Antony Blinken.

Swiss banks hold around $213 billion of Russian wealth, according to estimates. The two largest lenders, UBS and Credit Suisse each hold tens of billions of francs for Russian clients.