WASHINGTON –Special envoy to Afghanistan and Pakistan  Richard Holbrooke told the Senate Foreign Relations Committee Wednesday that  the Afghan government is on schedule to take over some civil and security functions in time for a planned U.S. military withdrawal next July, but lagging in others.

Committee chair Sen. John Kerry, D-Mass., and Sen. Richard Lugar, the top Republican on the committee, questioned Holbrooke repeatedly on U.S. expectations for Afghan President Hamid Karzai and what conditions must be present for a military drawdown to take place.

“In some areas we’re on schedule, in some areas we’re behind,” Holbrooke said. Retention of Afghan police officers is improving, but it’s unclear whether the upswing is seasonal or will be sustained, he said. He also pointed to improved availability of electricity and a growing economy in Afghanistan.

On the other hand, he said, the Marja district in the Helmand province of southern Afghanistan is flagging in its number of judges and police.

But President Barak Obama “doesn’t want to pull this tree up by its roots every month to see how it’s doing,” Holbrooke said.

He said U.S. civilians will continue work to build the country’s traditionally strong agricultural base, strengthen the Afghan justice system and the rule of law, provide alternatives to opium production and build regional governance.

But senators pushed for more specifics on when the U.S. involvement in Afghanistan can end.

“What I feel because of this lack of clarity is that we’re in Afghanistan because we’re in Afghanistan and we don’t have the will to be successful and we don’t have the will to leave,” said Sen. Bob Corker R-Tenn. “I don’t understand and I’m very concerned and I hear a lot of mixed signals.”

The Karzai government has drawn increasing criticism that funds for reconstruction and development from donors and countries contributing to the International Security Assistance Force are enriching corrupt officials, warlords and people outside of Afghanistan.

Graft affects two thirds of households in Afghanistan and bleeds off about a 10th of the country’s economy, and has doubled since 2007, Integrity Watch Afghanistan found in a survey completed late last year and released on July 8.

Weak accountability systems stood out as the most commonly indicated source of corruption, with 63 percent of the survey’s 6,500 respondents over 32 of Afghanistan’s 34 provinces putting that above low civil servant salaries and large sums of money in circulation, according to the Kabul-based anti-corruption group.

Karzai has announced an upgrade to the office that is in charge of fighting corruption.

“It would be unfair to hold any one person accountable for the totality of events in this country,” Holbrooke said of the Afghan president. “I think he’s doing the best job that he can under the circumstances.”

Holbrooke left immediately after the hearing for a visit to Pakistan and Afghanistan to meet with Secretary of State Hillary Clinton, who was headed to the Kabul Conference on July 20 and 21, where she will meet with U.N. Secretary-General Ban Ki-Moon and foreign ministers from other countries with an interest in Afghan security.