Eldorado is developing the Skouries and Olympias projects in northern Greece, where it also operates the Stratoni mine. Skouries has been a particular flash point with the authorities, with differences lasting for years over testing methods applied to comply with environmental regulations.
"We will exhaust all legal means to get the necessary permits and I believe we will get them," Eldorado Chief Executive George Burns told Kathimerini's Sunday edition.
"If our differences cannot be sorted out in a friendly manner, I will do whatever it takes to defend our shareholders and our employees' interests."
Eldorado has applied for licensing but the energy ministry has said it would launch an arbitration process this month to ensure that the Toronto-based miner respects its contractual obligations.
"We want a good relationship with the Greek state. We have shown a lot of patience and we will continue to show patience," Burns said, adding the company had spent more than two billion dollars to acquire Greek assets and a further one billion dollars to develop them.
Greece, which has received three international bailouts since 2010, is seeking investments to rebuild its economy and help it emerge from years of deep economic crisis.
Publicly, its leftist-led government backs investment but investors often complain of hurdles such as excessive red tape and labor union and political resistance.
(Reporting by Angeliki Koutantou; Editing by Gareth Jones)