"The British ambassador should be cautious about his remarks and conduct with regards to making interfering statements which have never been part of the diplomatic framework," Iranian Foreign Ministry Spokesman Ramin Mehmanparast said at his weekly press briefing on Tuesday.
"As far as we know, the label is annually granted to a number of individuals and officials in Britain as a ceremonial title," he added.
The Iranian spokesperson emphasized that ambassadors and diplomatic officials have the mission to strengthen ties between countries, saying, "They should never take measures to damage ties and stir emotions."
The British envoy to Tehran was appointed by Queen Elizabeth as Knight Commander of the Order of St. Michael and St. George (KCMG) in the 2011 New Year Honors.
The move drew massive criticism from a large number of Iranian lawmakers who say the timing of the decision unveils the true nature of Britain's hostile and interfering policies regarding the Islamic Republic.
Meanwhile, Mehmanparast pointed to reports about the suspected death of Iranian prisoner Ali-Reza Asgari in an Israeli prison and held the Israeli regime accountable for the case.
Asgari, the former Iranian deputy defense minister, mysteriously disappeared in 2007 while on a trip to Turkey. He is believed to have been abducted and transferred to Israel.
The spokesman also pointed out that consultations are currently underway with Turkey to find clues about the fate of the missing Iranian.
He noted that Israeli media have officially confirmed that the former Iranian official has been kept in prisons of the regime, reiterating, "Israel is responsible for Asgari's safety."
On Thursday, Salehi also called on the United Nations for assistance in the case of Asgari, stressing that Israel must be held accountable for the health and safety of the former Iranian official.