Ukrainian President Volodymyr Zelensky on Thursday said that Kyiv wanted "honesty" in its ties with NATO, as he began a tour of countries ahead of a key summit of the Western military bloc.

Zelensky is seeking NATO accession for his country, which has been battling with the Russia-Ukraine war since February 2022, and has said that Kyiv wants to receive an "invitation" to join the bloc at next week's summit in Lithuania.

"We need honesty in our ties," Zelensky told reporters in Prague, alongside Czech President Petr Pavel. He said it was time to demonstrate "the courage and strength of this alliance."

"We need this motivation," he added.

The summit is expected to take decisions to establish a NATO-Ukraine council and individual allies will provide security guarantees to Kyiv, including economic and military assistance.

Zelensky urged NATO to show its "strength and unity" ahead of its summit in Vilnius, calling on it to give Ukraine a "clear signal".

"Ukraine does not have an invitation in one form or another," Zelensky said.

Pavel, a former head of the NATO Military Committee, said Ukraine should start NATO accession talks as soon as the war is over.

"Ukraine will sit there alongside NATO countries as equals, and the communication between NATO and Ukraine will reach a new level," Pavel said.

He also hailed Ukraine's efforts, saying the country has "not only launched a counteroffensive, but it has shown that Russia is by far not as strong as it was trying to make itself seem to us all."

Earlier Thursday Zelensky paid a visit to Bulgaria, a major arms maker and ally, meeting Prime Minister Nikolay Denkov and President Rumen Radev for talks.

On Friday, the Ukrainian president will meet Czech Prime Minister Petr Fiala and parliament speakers, before heading to Turkey for his first visit since Russia's invasion and talks with his counterpart Recep Tayyip Erdogan.

Zelensky said on Telegram the talks would focus on "the security of our countries and our entire Europe, defense support and defense cooperation".

Bulgaria and Ukraine also signed a joint declaration on the Euro-Atlantic integration of the war-torn country and a memorandum of cooperation in the field of energy.