The White House's special representative to Afghanistan and Pakistan held talks with government leaders in Islamabad on Thursday, days after the capture of the Afghan Taliban's No.2 in Pakistan.
Mullah Abdul Ghani Baradar was picked up in the southern city of Karachi this month in a raid by Pakistani and US agents, the most senior Taliban commander ever arrested in Pakistan.
US special representative Richard Holbrooke, on his second visit to Pakistan this year, met Pakistani Prime Minister Yusuf Raza Gilani for talks that included security issues, Gilani's office said.
The previous day in Kabul, Holbrooke called the arrest of Baradar "a significant development".
"We commend the Pakistanis for their role in this and it is part of a deepening cooperation between us," he said.
Holbrooke was due to meet other leaders and talk to reporters later in the day.
US ally Pakistan is battling its indigenous Taliban militants but has taken little action against Afghan Taliban operating from its soil who are not fighting the Pakistani state.
The al Qaeda-backed Pakistani Taliban, who are loosely allied with the Afghan Taliban, have launched a wave of bomb attacks across Pakistan in retaliation for military offensives on their strongholds.
On Thursday, at least 20 people, including the commander of a militant faction which is not part of Pakistan's main Taliban alliance, were killed in a blast in a remote village in the Khyber region on the Afghan-Pakistan border.
Security officials said the blast appeared to be related to factional rivalry.
Baradar's capture came as US forces spearhead one of NATO's biggest offensives against the Taliban in Afghanistan.
It also comes as momentum builds for talks with the Taliban to end a war Western force commanders say they can't win militarily.
Pakistan wants to play a leading role in any Afghan peace process and keep the influence of old rival India at bay.
The government has said little about the rare arrest of a top member of a Taliban leadership council the United States says has been operating in Pakistan for years.
The army confirmed the arrest in a terse statement on Wednesday but gave no details, citing security reasons.
Although denying any support for its old Afghan Taliban allies, Pakistan has long turned a blind eye to their members and support networks in the belief the Taliban represent the only leverage it has over Afghanistan.
Analysts said the Baradar's arrest should bolster Pakistan's position as it manoeuvres to play a role in any Afghan peace process, but it probably did not signal a fundamental Pakistani policy shift.
"This could be a gesture to show the international community that Pakistan is capable of dealing with the Taliban. They'd like to take this opportunity to exert their position vis-a-vis Afghanistan and vis-a-vis India," said Khadim Hussain of the Aryana Institute think tank.
In another sign Pakistan might be doing that, an Afghan official said two Afghan Taliban provincial "shadow governors" had also been arrested in Pakistan this month.
Mullah Abdul Salam and Mullah Mir Mohammad, respectively the shadow governors of the northern Afghan provinces of Kunduz and Baghlan, happened in Pakistan's Baluchistan province, Mohammad Omar, the Afghan governor for Kunduz, told Reuters.
Pakistan's military spokesman said he had no information about any arrests.
While the arrests would appear to signal a more cooperative Pakistan, they were unlikely to herald a big shift in policy.
"I don't see any major change in Pakistan's policy on links with the Taliban as yet because things are still very fluid," said Rahimullah Yusufzai, a veteran journalist and expert on militancy.
In another indication of the pace of unfolding events, on Wednesday officials in Kabul and in the Maldives, the Indian Ocean state, said Taliban-allied representatives and members of
Afghanistan's parliament held talks at a resort there in January.
Arsala Rahmani, a former Taliban official who is now a member of Afghanistan's parliament, was one of those who attended.
He said mediators had told the militants' representatives they should present a united front and conduct talks in consultation with the government and not through other channels.
He did not elaborate but analysts say Kabul is suspicious of any Pakistani involvement. No date or venue was set for another meeting, he said.