The German foreign ministry recommended that tourists "take sufficient amounts of cash" when visiting Greece, a top vacation spot for European tourists.
The advice came before Greek Prime Minister Alexis Tsipras announced on Sunday night that banks in the country would close on Monday, a consequence of the decision on Saturday by the eurozone's finance ministers to halt Greece's financial bailout programme.
The banks are expected to remain closed for a week, while limits on withdrawals by Greek residents from cash machines have been set at €60, according to media in Greece.
(The Greek government stated that this limit would be waived for visitors.)
The Athens Stock Exchange will also shutter its doors on Monday.
Tsipras called the eurozone finance ministers' decision a "denial of the Greek public's right to reach a democratic decision", referring to a planned July 5th referendum, when citizens will vote on the last offer made by Greece's creditors before talks broke down.
But he insisted that "the savings of citizens, the salaries and the pensions are guaranteed".
In the wake of these developments holiday-makers will need to keep tabs on the evolving situation and check for any updates on travel recommendations.
After talks in Brussels broke down in acrimony on Saturday between Athens' left-wing leaders and the rest of the eurozone, Greece is hurtling towards a default with its EU-IMF creditors.
The ECB has refused to increase emergency cash available to Greek banks despite a bank run being underway.
This has put pressure on the government to impose capital controls to prevent a collapse of its lenders.
Many bank cash machines in Greece were already empty and there were long lines at those still working on Sunday.
Meanwhile, Britain's foreign office warned travellers "of the possibility that banking services - including credit card processing and servicing of ATMs - throughout Greece could potentially become limited at short notice."
It said "make sure you have enough euros in cash to cover emergencies, unforeseen circumstances and any unexpected delays".
With the capital controls imposed, businesses may not want to accept credit cards any longer as they could have trouble accessing bank accounts, even if card transactions are authorized.
"There is some information according to which some restaurants and filling stations haven't accepted card payments for some time and are taking just cash," said the Swedish foreign ministry.
Polish Prime Minister Ewa Kopacz last week urged Poles visiting Greece to "not rely only on cards and ATM machines . . . best to take cash with you."
Denmark, Finland and the Netherlands also warned their nationals not to rely on cards and take cash when visiting Greece.
Earlier, Andreas Andreadis, President of the Greek Tourism Confederation, said that so far "nothing has changed".
He said "foreign clients have no problems with money transactions" and that "their credit cards won't be compromised by capital controls."
However, he said his group would set up a help line for hotels so they could better advise guests.