Lithuanian Prime Minister Saulius Skvernelis new cabinet of political outsiders was sworn in Tuesday, with rising defence fears over Russia and social woes topping the agenda in the eurozone and NATO member.

Former police chief and interior minister Skvernelis, 46, leads a cabinet formed by his Peasants and Green Union (LPGU) and the junior Social Democrats, following his party's surprise election win in October.

The LPGU, previously an outsider party with only one seat in parliament, ended two decades of domination by Social Democrats and conservatives when it swept to victory with pledges to invest in the regions and abandon controversial labour reforms.

The new government won a confidence vote Tuesday with the support of 86 lawmakers in the 141-seat parliament, while three voted against and 40 abstained.

The cabinet faces growing concerns over Russia, which has heavily militarised the neighbouring Kaliningrad exclave.

Skvernelis has pledged to meet NATO's two-percent-of-GDP funding target by 2018, a point that US President-elect Donald Trump said he would press with European allies.

The new premier has also left Social Democrat Foreign Minister Linas Linkevicius, a vocal critic of Moscow, in his post.

The cabinet has pledged to fight social inequality and halt emigration to richer Western European nations.

"We want our social inequality index to reach the EU average at least," Skvernelis told lawmakers, adding Lithuania was third or fourth worst within the bloc in this respect.

The exodus from Lithuania -- much of it to Britain -- became a major campaign issue after the population shrank from 3.5 million in 2001 to 2.9 million in 2015, with further declines feared.

Skvernelis led the LPGU list into the election but has not joined the party, and many of his ministers are not party members either.

Conservatives and liberals, who remain in opposition, have accused Skvernelis of lacking a strategy to boost much-needed investment in the newest eurozone member.

"The lack of ambition poses the threat that the Lithuanian economy will fall into the middle-income trap," said conservative ex-premier Andrius Kubilius.