Miller met in Brussels with European Commissioner for Energy Gunther Oettinger and German Foreign Minister Frank-Walter Steinmeier.
Gazprom in a statement said both sides discussed a "wide range" of bilateral issues.
"The parties confirmed their interest in maintaining the mutually beneficial relationship built over the decades of successful collaboration," the Russian company said in a statement.
There was no public statement from Oettinger or the German foreign minister on the meeting with Miller.
European leaders have tried to add a layer of diversity to a natural gas market that's dependent on Russia. Ukraine's role as a transit nation for Russian gas has added to concerns about European energy security.
European officials have looked to supplies from gas-rich Azerbaijan as a Russian alternative, along with imports of liquefied natural gas.
Gazprom said in its statement it wasn't just a major gas supplier to Europe, with a 40-year track record of reliability. To date, it said, it's the only gas supplier to have invested "billions" of dollars in developing Europe's gas network.
Gazprom is moving forward with the South Stream pipeline, which would avoid Ukraine. European leaders said they're reluctant to embrace the project given the recent crisis involving Ukraine.