Thailand's cabinet approved a 105.3 billion baht ($2.97 billion) plan on Tuesday to build two new rail lines in Bangkok, part of a wider infrastructure push by the ruling junta as it seeks to boost a sluggish economy.

The Mass Rapid Transit Authority of Thailand had earlier put the cost at 111 billion baht ($3.14 billion) but reduced that estimate, citing lower construction work costs.

"We'll now look at the bidding process to ensure it takes place within the next three months," Transport Minister Arkhom Termpittayapaisith told Reuters.

The rail lines are part of the military government's infrastructure drive aimed at kick-starting Southeast Asia's second-largest economy.

The government has said more rail links are needed to reduce traffic congestion in Bangkok, which currently has three Skytrain lines and one underground line.

Construction of the new lines will be funded on a public-private partnership (PPP) basis.

The Cabinet on Tuesday also approved a measure aimed at boosting domestic spending between April 9 to 17, part of the Songkran Festival or Thai New Year, by allowing Thais a tax deduction of up to 15,000 baht on items such as hotels and food while travelling domestically.

It also renewed a round-the-year tax deduction of up to 15,000 baht for domestic travel.

Thailand's central bank on March 23 cut its 2016 growth forecast to 3.1 percent, as the economy was losing steam and still faces global risks.