Washington (CNN) -- A senior State Department official conceded Wednesday that, "This was a rough week for American diplomacy."

The official, speaking with reporters in a conference call, said the WikiLeaks disclosures of State Department diplomatic cables "have done substantial damage."

"We'll probably never have a neat scorecard to show you with meetings not granted, confidences not shared, cooperation that's hedged or denied," he said, "and it is going to take time and hard work to rebuild trust...we've got a tough road ahead of us and a lot of rebuilding to do."

The official described what he called a "grueling" effort by Secretary of State Hillary Clinton to contain damage from the leaks. Clinton, he said, has made several dozen calls to world leaders "to express our deep regret and underscore steps we've taken to ensure confidentiality and underscore important diplomatic work before us."

State Department officials in Washington and at embassies around the world, he said, have reached out to a total of 186 governments to reinforce Clinton's message, adding "to virtually everyone who takes our calls."

The secretary, currently traveling in Central Asia, is attending two conferences during the trip, meeting with world leaders. The senior official said the effort is "grueling at best, but there is no more effective way of demonstrating our commitment to diplomacy than actually doing it."

Clinton, he claims, "is uniquely positioned" for the task: "She has the political skill to navigate what are inevitably tough conversations, the credibility to address foreign audiences, the resolve to do the really hard work of dealing with this head-on and the political experience, I think, to connect with foreign leaders on these leaks in a way that others can't."

The State Department, along with other agencies of the U.S. government, he explained, is taking steps to control access to classified information, trying to find the proper balance between the "need to know" and the "need to share."

"When you look at a reality like the fact that an Army private serving in a unit in Iraq can have access to confidential cables coming from embassies in Latin America or Russia or other parts of the world," he said, "that really don't have any bearing on the very important work at hand in Iraq ... I think we have to take a very careful look at what kinds of measures we need to take to fix that balance."

Procedures already in place at the State Department before the leaks were known "have been vindicated," he said, "including our long-standing policy of preventing employees from downloading materials from classified terminals except in very carefully controlled circumstances."

The official also defended the department against charges that a directive issued from the Secretary's office to diplomats to collect information on foreign diplomats working at the United Nations blurred the line between diplomacy and espionage. The directive was contained in a leaked cable.

"The fact is we do not ask our officers to perform duties outside of accepted diplomatic practice," he said. "The State Department often conveys requests on behalf of the entire inter-agency community. These kinds of wish-lists are aimed at entire missions overseas which include typically a number of government agencies. For diplomats the laundry lists are informational. They are not instructions."

But the official also explained that the department, as a part of its review of its practices in the wake of the WikiLeaks revelations, is re-thinking this. "We're obviously taking a careful look at how those kinds of requests are conveyed and handled."

"We've got a tough road ahead of us and a lot of rebuilding to do," the official said. The leaks are going to complicate U.S. diplomacy and international cooperation for a long time after the headlines fade."