Merkel cautioned Cyprus against "exhausting the patience of eurozone partners" during a meeting Friday with the parliamentary group of her junior Free Democratic Party coalition partners, participants told news agency AFP.
She also complained at the talks that the Cyprus government had not been in contact for days with its international creditors, the European Union, the European Central Bank and the International Monetary Fund, the participants said.
Merkel rejected the Cyprus government's proposal to involve pension funds in the country's rescue plan and was reported by participants to have said: "The EU must in no way abandon its principles."
Her comments were confirmed by other sources within her conservative party reported by the DPA news agency.
German Finance Minister Wolfgang Schäuble has expressed scepticism about the Cyprus government's "Plan B" to avoid financial meltdown, the mass-circulation daily Bild reported Friday.
"Cosmetic changes alone are not enough," the newspaper quoted Schäuble as saying, citing government coalition members who took part in a meeting with the minister late on Thursday.