Iran threatened to reciprocate Kuwait's decision to expel most of its diplomats on Thursday, saying the accusations that Tehran was behind a terrorist cell in the country were "baseless".
"Iran's strong objection has been communicated to Kuwait's charge d'affaires. It was reiterated that Iran reserves the right to a reciprocal measure," said foreign ministry spokesman Bahram Ghasemi in a statement on his Telegram channel.
A senior Kuwaiti official had earlier told AFP that 15 Iranian diplomats had been asked to leave the country.
The move follows a court case in which 21 people were found guilty of belonging to a cell that had been formed and trained by Iran's Revolutionary Guards, which Tehran has denied.
"It is regrettable that Kuwaiti officials, in this sensitive situation in the region, instead of making an effort to reduce useless tensions... have targeted the Islamic republic with baseless accusations," an Iranian foreign ministry official told the Kuwaiti charge d'affaires during their meeting, according to Ghasemi.
News agency IRNA said there were currently 20 diplomats working at Iran's embassy in Kuwait.
It has not been confirmed whether Iran's ambassador Alireza Enayati is among those being expelled.
Kuwait greatly reduced its diplomatic presence in Tehran last year after its ally Saudi Arabia completely severed relations with Iran, keeping only a charge d'affaires and two officials, according to IRNA