Carl Bildt has furthermore added that Sweden has responded by blocking the arrival of the new Belarus ambassador and by expelling two diplomats.
Writing on his blog, Bildt described the decision to expel the Swedish ambassador Stefan Eriksson as a "serious breach of protocol".
"It is no secret that our relations with the Minsk regime are strained. And the situation has become even more tense since the seriously fraudulent presidential election in December 2010 and the political prisoners that we have since noted."
Carl Bildt admitted that Sweden, along with other EU countries, maintains a "relatively extensive" programme of support for civil society groups in Belarus.
"Not least to organisations which work with human rights in Belarus," he wrote.
Swedish relations with Belarus have been in stark focus recently after Stockholm-based PR company Studio Total dropped 879 teddy bears bearing various messages calling for freedom of expression from a light aircraft in early July.
President Lukashenko was at first loath to accept that the flight was real and that the country's air-space had been breached.
But on Thursday President Alexander Lukashenko sacked two of the nation's top defence officials after calling a meeting last week to scold his staff for allowing what he described as a "provocation".
Studio Total on Friday expressed the belief that the expulsion of the ambassador was a direct result of their teddy bear flight.
"That seems logical," Studio Total founder Tomas Mazetti told the Expressen daily.
However Martin Uggla, an expert on Belarus at the Swedish human rights NGO Östguppen, argued that the decision has more profound reasons.
“It's a bigger issue than that. Sweden has criticized Belarus for abusing human rights for a long time. Now they want to punish Sweden," Uggla told The Local.
“Now they want to cool off the escalating criticism that they have received."
Uggla observed that Sweden's ambassador has held a high profile concerning the issue of human rights in Belarus.
"Stefan Eriksson has had a significant profile in Belarus and been openly criticizing them for abusing human rights for a long time," adding that he expects Eriksson to continue this work from at home in Sweden.
Carl Bildt confirmed that Eriksson will remain as Swedish ambassador to Belarus but will be be based in Stockholm for the time being.
"Now with a clearer focus on democracy and freedom of speech issues in Belarus," he said.
Bildt revealed that he had been asked by the Belarusian foreign minister to promise to reassign ambassador Eriksson future when they met at an EU meeting on July 23rd.
"He explained that his president was getting increasingly irritated and referred both to the fact that ambassador Eriksson had attended a meeting organized by the opposition, and that we at the embassy had given support to volunteer groups."
"I of course dismissed any suggestion of such an agreement," Bildt proclaimed.
Carl Bildt furthermore defended Sweden's right to maintain contact with civil society groups, pointing out that he presumed the Belarusian embassy in Stockholm also maintained similar contacts in Sweden.
Bildt stated that the decision will be discussed by the EU and that Belarus will suffer various consequences after Friday's events.
Alexander Lukashenko has ruled Belarus with a iron fist since 1994, basing much of his hard man reputation on the defence of the nation's borders, including the capabilities of the joint air defence system it shares with Russia.
Valery Karbalevich, an independent Minsk-based political analyst, explained the move to purge the generals as an attempt to save face in front of Moscow.
"It looks like Moscow is cranking up pressure and demanding an answer as to why the much-acclaimed air defence system is riddled with holes," Karbalevich told the Associate Press news agency on Thursday.
Peter Vinthagen Simpson
With additional reporting by Salomon Rogberg.