Mexico's transport and communication ministry (SCT) is reallocating 7.39bn pesos (US$387mn) to the Mexico City government to build the Mexico City-Toluca rail line.
Of the amount, 4.83bn pesos were reallocated in April this year, while 2.55bn pesos will be reassigned between June and December this year, according to figures in the official gazette.
The ministry has said the cost of the project has risen to 44bn pesos from 42.7bn pesos last November.
The 58km line from Toluca to Observatorio station in Mexico City is currently 33% complete and should have advanced 75-80% by the end of this year, the SCT has said.
The ministry will carry out tests on the first phase of the line in December. Operations are due to start in April 2018, a year later than originally scheduled.
The interurban railway will have capacity to transport 230,000 people a day. Travel time is expected to be 39 minutes and trains will reach speeds of up to 160km/h.