A key question to be raised at the gathering on July 11-12 will be the future relationship between Ukraine and NATO, Scholz said.

"We should look soberly at the current situation," Scholz told lawmakers in Berlin, noting that Kyiv "has itself said that a NATO membership is not in the question while Russia is carrying out its war against Ukraine".

"That's why I am putting forward that we focus in Vilnius on what is now an absolute priority -- that is, to strengthen the fighting power of Ukraine."

Parallel to that, Scholz said Germany will work with the G7 and EU partners as well as Kyiv to work out "effective and long-term security commitments".

These will ensure that Ukraine gets sustained military support as well as the necessary economic strength to defend itself against Russian aggression, he added.

The Vilnius talks, he said, will send a "strong signal" of transatlantic cooperation and determination.

Germany, which for years has fallen under the NATO two-percent spending goal will finally meet the target from next year.

"We will ensure that the Bundeswehr finally receives the equipment it needs... also by spending two percent of our GDP on defence for the first time in decades, starting next year," Scholz vowed.

Germany's defence spending has reached only around 1.5 percent in the last years, but Russia's war in Ukraine has sparked a major policy shift in Berlin.

Besides sending armaments to Ukraine, Germany is going on a military spending spree to replenish its worn-out stocks, from fighter jets to tanks to air defence systems.

Ahead of the Vilnius meeting, Scholz also urged Turkish President Recep Tayyip Erdogan to end his opposition to Sweden's bid to join NATO.

Sweden should "sit at the summit table" as a new NATO ally, Scholz told the Bundestag.

"And I call on the re-elected Turkish President Erdogan to now clear the path for this, as we all decided together last year in Madrid."