A part of these costs has to be covered from the EU budget, according to the president.
"For Lithuania to meet its commitments in 2030, additional measures may require as much as 14 billion euros, of which almost 10 billion euros will have to be allocated from the state budget," Nauseda said at a foreign policy conference in Vilnius.
"This is a high price that we will not be able to pay all by ourselves," he added.
The EU aims to reduce greenhouse gas emissions at least by 40 percent by 2030. The individual target set for Lithuania is to cut these emissions by 9 percent.
The main challenges Lithuania faces in meeting these commitments come from an increase in areas of arable land in the country and its old vehicle fleet.
Nauseda is leaving on Thursday for an EU summit to hold talks on climate change and the bloc's next multiannual financial framework.
The EU's member states will discuss whether to approve the commitment to shift to a climate-neutral economy by 2050.
The Lithuanian president and the Latvian and Estonian prime ministers warned in a joint letter in late November that EU spending cuts in the next budget would undermine climate change ambitions.
Lithuania sees the current EU budget proposals as unacceptable, mainly due to the proposal to slash cohesion policy funding for the country by around one-fourth.
"Such ideas threaten to complicate structural reforms and, unfortunately, implement the 'two-speed Europe' model, which is definitely not something we want," Nauseda said on Wednesday.
According to the president, Lithuania is firmly committed to the goal of a climate-neutral economy by 2050, but "transformations of this scale require sustainable financing that must be envisaged in the multiannual financial framework".
"The same rules must apply to all member states, including access to support from the Just Transition Fund," he said.
Talks on the bloc's next multiannual budget are expected to be completed next year.