The Hague, Netherlands (CNN) -- Bosnian Serb genocide suspect Ratko Mladic dismissed as "obnoxious" charges against him Friday during his first appearance at a war crimes tribunal.

Mladic appeared in court dressed in a gray striped suit, a matching tie and a military cap, which he removed once he sat down. He listened impassively as a judge advised him he has the right to remain silent and then recited the charges to him. At times, he sipped water from a glass, his face showing no apparent emotion

"I would like to receive what you've read out just now, these obnoxious charges leveled against me," Mladic said. "I want to read this properly, to give it some proper thought together with my lawyers, because I need more than a month for these monstrous words, the ones that I've never heard before."

Mladic was the commander of Bosnian Serb forces during the civil war in Bosnia-Herzegovina, the bloodiest of the conflicts that accompanied Yugoslavia's breakup in the 1990s.

The 69-year-old is accused of leading a campaign of "ethnic cleansing" against Bosnia's Muslim and Croat populations that included the shelling of Sarajevo and the torture, abuse and rape of civilians.

More than 200,000 Muslims and Croats died in the 1992-95 conflict, including nearly 8,000 Muslim men and boys slaughtered at Srebrenica in 1995. It was Europe's worst massacre since World War II.

His court appearance at The Hague occurred days after he was arrested after more than 15 years in hiding.

During the appearance, he asked for more time to a enter plea, saying he needs more than the 30 days required so he can understand the charges. He was "gravely ill," he said, and had not yet read the documents relating to the charges.

The judge, Alphons Orie, scheduled another appearance on July 4 at the U.N. war crimes tribunal in The Hague. Mladic was asked whether there was any issue relating to his arrest or detention, or any other issue that he wanted to raise.

Mladic -- who repeatedly said he stood up for his country -- said he didn't kill Croats.

"I do not fear any journalist or any people, any nation or ethnicity. I defended my country and people ... now I am defending myself," Mladic said.

"If you want the proceedings to proceed as they should ... I just have to say that I want to live to see that I am a free man. And such as I am, I am defending my country and my people and not Ratko Mladic."

Serge Brammertz, the prosecutor of the International Criminal Tribunal for the former Yugoslavia (ICTY), said on Wednesday that Mladic's arrest "confirms that no one can have impunity for the crimes they've committed."

"I hear many people commenting that his arrest ends an important chapter for international criminal justice. But the process of establishing Ratko Mladic's accountability has only just begun."

Mladic was taken to The Hague on Wednesday, a day earlier after losing his fight against extradition from Serbia. He was charged with genocide, crimes against humanity and violations of the laws of war.

An amended indictment against him was filed on Wednesday to make sure charges "reflect the most recent developments in the tribunal's case law."

Brammertz said the transfer brings the tribunal closer to completing its mandate to capture those responsible for the most serious crimes in the former Yugoslavia.

"As a result of the arrest, today only one of the 161 persons indicted by the tribunal remains at large," Brammertz said, referring to Goran Hadzic, a political leader of the Serbian entity in Croatia during the mid-90s.

His lawyer, Milos Saljic, argues that Mladic would not be able to participate in a trial at The Hague because of his ill health.

Saljic said he wants his client examined by specialists, including a gastroenterologist, a cardiologist, a psychiatrist and a neurologist.

But Serbia's chief prosecutor, Vladimir Vukcevic, said the suspect was "lively and joking," and had asked for Russian classics to read while being held in Belgrade.

The suspect gave himself up without a fight May 26, despite having two handguns, according to Rasim Ljajic, the government minister in charge of searching for fugitive suspected war criminals.

Officials located Mladic in a village north of the Serbian capital after culling information from his former comrades and close family members. It is unclear what source led investigators to the former military commander.

The arrest clears a major hurdle that once stood between Serbia and its long-awaited entrance into the European Union, but the move could also usher in political backlash from the country's electorate, some of whom consider Mladic a hero.

The other fugitive war criminal suspects previously captured are Bosnian Serb leader Radovan Karadzic and former Serbian President Slobodan Milosevic, who died in jail in 2006 during his trial at The Hague.

Authorities say it's theoretically possible that the trials of Karadzic and Mladic could be merged.

CNN's Nic Robertson and Ivan Watson contributed to this report.