All three nations have been NATO members since 2004 and form a part of the Western defence alliance's eastern flank.

"We will increase our defence investment towards three percent of GDP," Latvian Prime Minister Krisjanis Karins told reporters after meeting with his Lithuanian and Estonian counterparts in Riga.

Wary of Russia after having spent decades under Soviet rule, the Baltic states are afraid they could be next on Moscow's agenda were it to win in Ukraine.

Estonia, Latvia and Lithuania currently spend a respective 2.34, 2.10 and 2.36 percent of GDP on defence, according to NATO estimates.

The three countries have different timelines for when they plan to achieve their target percentage.

Estonian Prime Minister Kaja Kallas said her country will exceed the three-percent mark in 2024.

"Our trajectory has been mapped out, as have our purchases," she said.

Latvia has not said when it plans to hit three percent, while Lithuania could reach it next year as budget rules allow it to borrow for that purpose.