During his recent visit to the United States, Lagumdzija acquainted his hosts in Washington with his suggestion about holding a conference like the 1995 Dayton peace conference.
Covic said that Lagumdzija's proposal could not bring anything good, assessing it as unrealistic in light of the international community's having grown weary of what he called political blockades in Bosnia.
"We must realise that Bosnia and Herzegovina is our problem," Covic added.
Politicians in the Bosnian Serb entity unanimously refused Lagumdzija's proposal. In Republika Srpska, it was seen as an attempt by the country's most numerous ethnic group, the Bosniaks, to abuse their majority over the two other constituent peoples -- the Croats and the Serbs.
The US Embassy in Sarajevo said on Wednesday there were no plans to organise a new peace conference on Bosnia and Herzegovina.
A new conference would require an agreement between the three constituent peoples. There are no plans for organising such a conference, the embassy said in a statement.
The statement said that negotiations in Dayton, Ohio, in 1995 were a historic event that produced a peace agreement establishing government in Bosnia and Herzegovina.
The Office of the High Representative (OHR) in Bosnia and Herzegovina said the country certainly needed constitutional reform to strengthen the functioning and efficiency of government, in accordance with the requirements of the European integration process.