Aid to Ukraine "is not evenly distributed now within NATO," Rutte told reporters in the Swedish city of Helsingborg ahead of a NATO foreign ministers' meeting.

"There is a limited amount of countries, including Sweden which is really punching above its weight when it comes to the support for Ukraine, and other countries like Canada and Germany, the Netherlands, Denmark and Norway and also a couple of others," he said.

"But there are also many not spending enough when it comes to the support for Ukraine," he said.

Last week, Rutte proposed that allies should dedicate 0.25 percent of their GDP to Ukraine.

The proposal, which could unlock tens of billions of dollars in additional aid, has faced strong opposition from some major member countries, according to news outlet Politico.

"The proposal will not get unanimity, so it will not work," Rutte acknowledged on Thursday.

"But it has at least started the debate between allies, that if we all are saying that Ukraine has to make sure that it stays in the fight as strong as possible, and bring this fight to a peace, then of course we all have to chip in an equal manner."

The Nordic and Baltic countries, as well as the Netherlands and Poland, devote a higher share of their GDP to military aid to Kyiv than many other allies, according to data from the Kiel Institute.