Foreign Minister Abdulaziz Kamilov of the Tashkent government said on Friday that they had given information about Rakhmat Akilov, 39, being radicalized after he moved to Sweden in 2014.
Kamilov did not confirm which nation they had provided their intelligence information to.
"During his stay abroad, he [Akilov] was recruited through the internet by emissaries of the international terrorist organization the Islamic State," Kamilov said during a news conference.
“According to the information that we have, he actively urged his compatriots to travel to Syria in order to fight at Islamic State's side," Kamilov continued.
Akilov applied for a Swedish residency permit in 2014, but was denied.
Earlier this week, an Uzbek security source told Sky News that Akilov had been detained at the Turkish-Syrian border in 2015, and was subsequently deported back to Sweden.
Four people were killed and 15 were injured as the hijacked truck was driven through a crowd outside a department store in a busy central area of Stockholm. Akilov was arrested in relation to the attack hours later, and quickly confessed to the terrorist act.
Last week, Swedish police verified that they had information on Akilov, but that they had not viewed him as a serious threat, despite his support for militant terrorist organizations including Daesh.
