"There will always be enough Turkmen gas for Russia," state news agency RIA Novosti quoted Lavrov as saying. "This is what the (Turkmen) president told me."
He made his comments upon his return from a two-day official visit to Ashgabat.
Russia had served as the primary importer of Turkmen gas. That relationship was strained, however, following a Turkmen pipeline explosion in April that Ashgabat blamed on Gazprom.
Nevertheless, Moscow said earlier this year that it intends to purchase more than 1 trillion cubic feet of Turkmen gas.
Both sides agreed to work on the construction of pipelines to transport natural gas from fields in the Turkmen waters of the Caspian Sea and Kazakhstan.
In December, meanwhile, Chinese President Hu Jintao joined the leaders of Turkmenistan, Kazakhstan and Uzbekistan for the inauguration of a 1,138-mile pipeline to deliver gas from Turkmenistan to China. The route for that pipeline bypasses Russian territory.