The announcement was made just hours after Nehammer became one of the first western leaders to visit Ukraine, where he met with Ukrainian leader Volodymyr Zelensky.
Nehammer will meet with Putin on Monday, making him the first leader to meet personally with the Russian leader since he ordered the invasion of Ukraine.
Speaking with German tabloid Bild, the deputy mayor of Mariupol, which has faced a weeks-long siege from Russian forces, said the visit was “not appropriate”.
“The war crimes that Russia is currently committing on Ukrainian soil are still taking place,” Sergej Orlow said.
“What we saw in Bucha may have been worse in Mariupol, even if the Russian army is trying to cover up the crimes. I don’t understand how it is possible to have a conversation with Putin at this time, how to do business with him.”
Nehammer said he hoped to put an end to the war with his visit, while he promised to raise the issue of war crimes.
“As a small, neutral country, we have a high degree of credibility as an intermediary and also a good reputation as an honest broker,” Nehammer said.
“We are militarily neutral, but not when it comes to naming crimes and when it comes to going where injustice is actually happening.”
A Ukrainian diplomat told Bild Nehammer was “overconfident” in his ability to change Putin’s mind.
“What overconfidence on the part of the Austrian Chancellor that he seriously believes there is any point in traveling now that Putin has shown what a brutal war criminal he is.”