"This is something we are watching very closely, and this really is a red line for us - as regards the prospect of Ukraine joining NATO," Peskov told the Ekho Moskvy radio station.
Peskov said that Moscow and Washington agreed at the Geneva summit that they needed to hold talks on arms control as soon as possible.
As it was reported earlier, the conversation between two presidents took place in Geneva on June 16. The American delegation included US State Secretary Anthony Blinken, while the Russian delegation was represented by Russian Foreign Minister Sergei Lavrov. The summit consisted of three parts. Ukraine was expected to be one of the topics of talks between the American and Russian leaders.
Secretary-General of the Alliance Jens Stoltenberg stated that the Alliance's relations with Russia have deteriorated recently.
NATO leaders have confirmed the decision of the Bucharest summit about Ukraine becoming the Alliance member. At that, Kyiv still needs to move forward with reforms, reads the document.
In April, President of Ukraine Volodymyr Zelensky discussed his country's membership in NATO with his French colleague Emmanuel Macron and British Premier Boris Johnson.