"If Russia wants to improve relations it needs to first acknowledge its responsibility for this attack and cease its recklessly aggressive behavior," Nauert told reporters.
Meanwhile, the United States and its allies have so far expelled a total of 151 Russian diplomats over the poisoning of former Russian spy Sergei Skripal, US State Department spokesperson said.
"Alongside our own announcement, you’ve seen an unprecedented wave of similar actions and expulsions taken by other governments, our global partners and our allies. The United States, the United Kingdom, NATO and now 25 other countries have so far announced the expulsions 151 Russian personnel," Nauert said.
"We informed them in a professional fashion of our decision, we have not heard anything formally from them," Nauert told reporters.
Earlier this week, over 25 countries, of which included numerous EU member states and the United States, announced their decision to expel Russian diplomatic workers after London stated that it was "highly likely" that Moscow was responsible for poisoning of Skripal and his daughter in the UK town of Salisbury earlier in March.
Russia, in turn, has strongly rejected the accusations and offered assistance in the investigation. However, Moscow's request for samples of the chemical substance allegedly used to poison Skripal has been rejected.
