A combination photo shows Bosnian Serb wartime leader and indicted war crimes suspect Radovan Karadzic (L) in an undated recent file photo and (R) attending a parliamentary session in the Republik of Srpska in Bosanski Samac February 13, 1995. (Xinhua/Reuters Photo)

World opinion mixed on Tuesday after the arrest of former Bosnian Serb leader Radovan Karadzic.

The Russian foreign ministry on Tuesday said that the arrest of Karadzic was "an internal matter" for Serbia, and the trial of Karadzic should be "impartial," accusing the UN war crimes tribunal of "an often biased approach."

"We hope the inquiry and the trial... will be impartial. We underline this since the International Criminal Tribunal for the former Yugoslavia (ICTY) has shown an often biased approach," the ministry said in a statement.

The ministry also said that the ICTY should be curtailed, adding that countries of the region were "mature and able to investigate independently."

Meanwhile, the U.S., the European Union (EU) and NATO have voiced their welcome.

The U.S. congratulated the government of Serbia on the capturing of Karadzic, calling his arrest a "tribute" to the victims of atrocities there.

"This operation is an important demonstration of the Serbian government's determination to honor its commitment to cooperate with the ICTY," according to a White House statement released on Monday.

EU foreign policy chief Javier Solana said on Tuesday that the arrest showed Belgrade was cooperating fully with the U.N. war crimes court in The Hague.

NATO Secretary-General Jaap de Hoop Scheffer urged Belgrade to ensure his swift extradition to The Hague and to step up pursuit of former Bosnian Serb military commander Ratko Mladic and other indicted war crime suspects.

German Federal Foreign Minister Frank-Walter Steinmeier on Tuesday described Karadzic's arrest as a "milestone" in relations between Serbia and the EU, hoping that Karadzic would be handed over to the ICTY.

Karadzic, 63, has been the leader of Bosnian Serbs during the 1992-1995 Bosnia War, and was indicted by the ICTY in 1995 of genocide during the war. The former Bosnian Serb leader was arrested on Monday night in a Belgrade suburb, 13 years after his indictment.

Editor: Yan