Negroponte told a congressional hearing Thursday that al-Qaida remains the largest threat facing the United States and leaders of the organization are hiding out of the U.S. military's reach in Pakistan, The Washington Post reported.
He said there have been successes in the Bush administration's war on terrorism, including the death of al-Qaida in Iraq leader Abu Musab al-Zarqawi.
However, violence in Iraq has risen steadily since the death of Zarqawi and U.S. Army Lt. Gen. Michael Maples said at the hearing that al-Qaida "has consistently recovered from losses of senior leadership" and that its "increasing cooperation with like-minded groups has improved its ability to facilitate, support and direct its objectives."
Maples said Iraqi security forces have been infiltrated by Shiite militias and are therefore "presently unable to stand alone against Sunni insurgents, al-Qaida in Iraq" or sectarian militias.
Negroponte said sectarian violence has become the country's largest problem.