Speaking at the end of a three-day visit to the Balkans, undersecretary of state Nicholas Burns said he hoped Mladic's days were numbered.
"My strong impression from our discussions here in Belgrade is that the [Serb] government is working very seriously to find General Mladic and there will be a sincere attempt to capture him or to have him voluntarily surrender and to send him to The Hague," Burns said.
He said that Washington would now release $10 million in aid to Serbia-Montenegro. That money was frozen in January because of Serbia's failure to arrest and extradite top war crimes suspects to the ICTY in The Hague.
Washington's optimism is based on a spate of surrenders of suspects and the impact of a videotape released last week on public opinion. The video, which appears to show Serb paramilitaries executing six Muslim prisoners, horrified many Serbs when it was shown on national television.
Not least, it seems, Rasim Ljajic, Serbia's human rights minister and the head of the government's body for cooperation with the Hague tribunal. Ljajic appears to be saying everything Washington wants to hear.
"I hope that by the end of the year we will put an end to the problem we have with the Hague Tribunal," Ljajic said. "The most important thing is that there is no longer any dilemma that all indictees will be in The Hague and that there is absolute readiness and political will from the state to fulfill this obligation. The only limiting factor is to determine whether The Hague fugitives are really in Serbia-Montenegro."
Part of the difficulty in tracking down former war criminals has been the reluctance of many Serbs to acknowledge that war crimes ever took place.
The videotape may change some of that. Since it was screened on Serbian television, both the Serbian president, Boris Tadic, and the prime minister, Vojislav Kostunica, have expressed their horror and determination to bring those responsible to account.
Yesterday, too, the Bosnian Serb government for the first time admitted that police forces from Serbia took part in the massacre of up to 8,000 Muslims at Srebrenica in 1995.
It may be that the video will create the climate for the Serbian authorities to be more proactive approach in seeking out those wanted for questioning in The Hague.
Yet, for all that, popular support for men like Mladic remains remarkably strong. On the streets of Belgrade, there are many who still regard the commander of Bosnian Serb forces as a hero -- not a war criminal.
"They shouldn't try to arrest him. He [Mladic] was defending Serbian people, after all," said one elderly man in Serbian.
Another, younger, Serbian-speaking man said: "I don't think [he will be arrested]. People won't give him up."
Ratko Mladic has been on the run since the arrest of Slobodan Milosevic, the former president of Yugoslavia, in 2001. But thanks to a combination of popular support and sympathy in high places he has kept one step ahead of his pursuers -- so far.
It may be, though, that the net is tightening. The calculation in Washington is that the carrot of financial aid and the stick of international opprobrium will persuade Belgrade to say it is time to deliver the elusive general to The Hague.