Greek leaders planned to shutter their banks for six business days starting Monday and impose strict limits on ATM withdrawals amid rising global concerns about the nation’s economic future.

Sunday’s decision to declare a bank holiday was a signal that Greece’s five-year battle to stay in the shared euro currency may swiftly be coming to an end, as leaders elsewhere urged steps to find a way to avoid that. Panicked citizens tried to pull their money from their accounts while they still could. ATMs in Athens were running out of money, and tensions were running high as Greeks stood in line for hours to scrape together cash for basic supplies. Lines mounted at gas stations as worried residents topped off their tanks for what could be a protracted period of time in a cashless nation.

“The decision not to prolong financial aid to Greece is offensive, and it’s a disgrace for Europe in general,” Prime Minister Alexis Tsipras said in a brief Sunday evening address broadcast across Greek television networks. He said he was seeking an extended and enlarged bailout from European lenders that would carry the country past Tuesday, when it will otherwise face default.

Tsipras said that the threat by European Union leaders to hold Greece to the deadline and not extend further assistance amounts to “blackmail.” But he gave no concrete indications that he had made any concessions that would change their minds.