Wall Street banks are getting a bit of Brexit relief from the European Central Bank as they step up preparations to move business from London.

The ECB said it’s taking into account the challenges of relocating during the coronavirus to offices in Frankfurt, Paris and across the European Union. With a year-end deadline for a Brexit trade deal looming, U.S. banks are reactivating plans to expand offices within the EU.

“We have been flexible in order to take into account the restrictions posed by the COVID-19 pandemic, in particular for the relocation of staff,” an ECB spokesperson said in a statement to Bloomberg. While recognizing the difficulties, the ECB said it remains “firm on the need for banks to reach their end-state target operating models.”

The ECB, which supervises the biggest banks in the bloc, has pressed firms to intensify their preparations and abide by deadlines to move. JPMorgan Chase & Co., Goldman Sachs Group Inc. and Morgan Stanley have relied on London for their European hubs for years.

Some finance employees who are earmarked to work from Brexit subsidiaries in Europe are still physically in London under European employment contracts as the virus interrupts their plans to move, Bloomberg reported this week.