Olson testified at his confirmation hearings Tuesday before the Senate Foreign Relations Committee, along with James Cunningham, nominated by President Barack Obama to be the next ambassador to Afghanistan.
U.S. relations with Pakistan, a key partner in the fight against terrorism, remain strained since U.S. forces killed al-Qaida leader Osama bin Laden inside Pakistan in May 2011. The United States faces escalating Taliban violence in Afghanistan as it prepares to end combat operations after a decade-long war by 2014 and bring home its troops.
The Haqqani network, which is connected to the Taliban, is a huge challenge for the United States, whose officials say the group's leaders use their Pakistani havens to launch attacks against U.S. forces and other areas in neighboring Afghanistan.
Washington has been pressing Pakistan to take tougher steps against the Haqqani network.
"I will certainly, if confirmed, take it as a central responsibility and the most urgent of my responsibilities to continue to press the Pakistani authorities on the Haqqani network in every way possible," Olson testified, The New York Times reported.
The Times said Olson and Cunningham, both senior diplomats currently based in Kabul, would have to handle a combination of tough and complex anti-terrorism, military and political issues if confirmed.
Cunningham, currently the deputy ambassador in Kabul, praised U.S. efforts in Afghanistan, while telling the senators there are still challenges in that country, the Voice of America reported.
"Today, the pieces of a long-term, enduring support structure for Afghanistan's continuing progress and development are now in place," he said. "This makes clear to Afghans and the region that the security transition does not mean we are abandoning Afghanistan. And the Taliban appear to be taking notice. For the first time in a decade, they are debating and signaling an openness to negotiations."
Olson and Cunningham both spoke of the need to convince Pakistan and Afghanistan the United States and its allies will not abandon the region after 2014, the Times reported.
Olson said despite current tensions, a stable and democratic Pakistan is in America's interest, VOA reported.
"Continued engagement with Pakistan is necessary to pursue the strategic defeat of al-Qaida ... Instability in Pakistan would undermine what we are trying to achieve in the region," he said.
The nominations of Olson and Cunningham come at a time of growing frustration in the United States about events both in Pakistan and Afghanistan.
Sen. John Kerry, D-Mass., who chairs the Senate committee, said at the hearing, "Obviously, there is no shortage of challenge here," VOA said.
Indiana Sen. Richard Lugar, the ranking Republican in the committee, expressed concern about continued, large-scale U.S. military commitments in Afghanistan at a time when there is a debt crisis at home.
Kerry predicted Olson and Cunningham would be confirmed, the VOA said.
Olson would succeed Cameron Munter, and Cunningham would replace Ryan Crocker.