"We are progressing. The project is going on satisfactorily. It is a priority project" for the government, Pietro Bagnati, Project Director for the Italian construction group Salini Impregilo, said according to a news report.
His firm leads the ArRiyadh New Mobility consortium, one of three foreign groups building the six-line Metro project planned to cover 179 kilometres (109 miles) of the sprawling, congested Saudi capital.
The underground and elevated rail network is to be supported by a bus system.
Asked if there had been any cuts to New Mobility's portion of the project, the Line 3 railway covering 42 kilometres, Bagnati said: "Our contract is still the same."
He spoke on the sidelines of the EU-GCC Business Forum which aims to strengthen trade and investment ties between the European Union and the six-nation Gulf Cooperation Council.
Analysts say Saudi Arabia made significant reductions last year in its capital spending, including infrastructure, to adjust to a collapse in oil prices since 2014.
This year's budget projects a rise in infrastructure and transport spending, to $13.9 billion from almost $10 billion riyals in 2016.
Construction on the Riyadh Metro began in late 2013 with 2018 targeted for completion. The Metro is considered to be the biggest infrastructure project in the history of the Saudi capital.
The government says it will finish paying early this year billions of dollars it owes to private firms, chiefly in the construction sector, after cuts to projects as oil revenues fell.