First Deputy PM and Foreign Minister Ivica Dacic stated this, adding that it was also ridiculous to say that Montenegro was "not making anti-Serb decisions, but those its own interest."
"I suppose Djukanovic means Montenegrin interests, which is nice - because Serbia is also making decisions in its own interest," Dacic told Podgorica-based daily Dan.
Serbian Interior Minister Nebojsa Stefanovic and Aleksandar Djordjevic, head of the Serbian Security Agency, BIA, denied on Wednesday any involvement in unlawful wiretapping, following claims by opposition leader Bojan Pajtic that his telephone calls had been intercepted.
Stefanovic said he was ready to resign if there is evidence that police had wiretapped the opposition leader.
"In anticipation of the visit of Prime Minister Aleksandar Vucic to the United States, we write to you with concern about reports of the deteriorating situation in Serbia," the five American Congress members wrote to Vice-President Biden in the letter which was made public by Serbian media portal Teleprompter on Monday.