"One of Lithuania's objectives is that the NATO summit agree on and confirm the so-called Vilnius commitment on defense investment of at least two percent," he told the public broadcaster LRT.
NATO's eastern flank nations are committed to spending a higher share of their GDP on defense, but other countries fail to reach even this threshold, according to Budrys.
The advisor's comment came after NATO Secretary General Jens Stoltenberg told the German news agency DPA that the Alliance's member countries would discuss their defense spending targets in the coming months.
"Some allies are strongly in favor of turning the current two percent target into a minimum," he said in an interview published on Tuesday.
Stoltenberg said he aimed to reach an agreement no later than NATO's next summit in the Lithuanian capital on July 11-12.
At NATO's gathering in Wales in 2014, the Alliance's member states agreed to aim for spending two percent of GDP on defense by 2024.
The Lithuanian government's 2023 budget allows raising defense spending up to 3 percent of GDP through borrowed funds, provided that the overall general government deficit for the year does not exceed 4.9 percent of GDP.
The country's defense spending was set at 2.52 percent of GDP in 2022.