Russian Energy Minister Alexander Novak has said construction of the so-called Turkish Stream gas pipeline might begin later than planned.

There is a risk not to start building the pipeline's first section on schedule the intergovernmental agreement is not signed in time, Novak is quoted by RIA Novosti as saying.

Gazprom CEO Alexey Miller had earlier explained that part of Turkish stream might become operational by December 2016, and his deputy Alexander Medvedev had added in April that the fourth (and last) section of the pipeline will be up and running by 2020.

This comes just a day after reports from Energy Ministry sources who say Moscow had sent to Ankara a document offering only an agreement on the first line of Turkish Stream. Apparently Novak did not comment on the claims.

Construction of Turkish Stream from the Russian side was officially announced in May, this being the first time Gazprom is embarking on implementing such a project without an intergovernmental agreement and other documents needed. Technically building the pipeline could begin either in June or July, Novak had pointed out last month.

Turkish Stream was announced last year as a substitute to South Stream, a project which was designed to carry gas to Europe via Bulgaria and other Eastern European states but which was ditched by Russia over Sofia's reluctance to issue construction permits.