After 16 years on the run, former Bosnian Serb military chief Ratko Mladic has made his first appearance before the U.N. war crimes tribunal at The Hague, telling judges he is “gravely ill” and calling the charges against him “obnoxious.”

Mladic was once a burly, intimidating figure on the battlefield. But he appeared subdued in court Friday, wearing a light gray striped suit as he listened as one of the judges slowly read the genocide charges lodged against him.

Mladic said he had not read the indictment against him and said he needed “a bit more time” to think about the allegations. If convicted, he faces life imprisonment.

He refused to enter plea to the 11 charges of war crimes and crimes against humanity, including genocide. Mladic, who identified himself as General Ratko Mladic in court, is permitted to delay his plea for 30 days or have the court enter a not-guilty plea on his behalf.

Mladic is accused of masterminding the 1995 Srebrenica massacre of 8,000 Muslim men and boys — Europe’s worst mass killing since World War II — and the 44-month siege of Bosnia’s capital of Sarajevo in which 10,000 died.

Mladic has been at The Hague since Tuesday after being flown there from Serbia where he was arrested last week.

In advance of the hearing, his court-appointed attorney, Aleksandar Aleksic, said Mladic has not had proper health care for years. Aleksic said Mladic spent Thursday night in a prison hospital, but the tribunal said Mladic’s medical supervision was routine.

The lawyer said he would ask the war crimes tribunal to approve more medical tests for his 69-year-old client. The exact state of Mladic’s health sparked a dispute when another of his attorneys, Milos Saljic, said he has a document claiming that Mladic suffered from lymph node cancer and underwent surgery for it in 2009.

But a Serbian prosecutor, Bruno Vekaric, said the document “looks like a hoax.”