The UN secretary-general has arrived in Pakistan for key talks expected to focus on regional security.
The UN head has said he will launch "very shortly" an independent inquiry into the killing of former Pakistani Prime Minister Benazir Bhutto.
Ban Ki-moon is also expected to discuss a possible UN commission into the murder of former Pakistani PM Benazir Bhutto in December 2007.
Ban Ki-moon's comments came after talks with senior Pakistani government officials in Islamabad.
Her supporters have consistently called for a UN probe into her death.
Ms Bhutto was killed in a suicide attack on a rally in 2007. Her death triggered riots across the country.
Mr Ban began his regional visit earlier in the day in Afghanistan, where he said the country would be a priority for the UN in 2009.
Five people have been arrested in connection with the killing, but no-one has been convicted.
Mr Ban's visit to Pakistan is his first since taking office in 2007.
He is meeting Prime Minister Yousuf Raza Gilani and President Asif Ali Zardari before leaving for India.
His visit comes amid growing unrest in Pakistan's border areas, with Taleban rebels attacking Nato supply routes into Afghanistan while government forces engage the Taleban in the Swat valley of North West Frontier Province.
'Safe release'
Officials say that Mr Ban is also expected to discuss last year's attacks on the Indian city of Mumbai (Bombay) which left more than 170 people dead.
Also on the agenda is the kidnapping of a UN official in the province of Balochistan on Monday.
Mr Ban has called for the "immediate and safe release" of John Solecki, the head of the UN refugee agency (UNHCR) in the city of Quetta who was snatched at gunpoint after his driver was killed.
A foreign ministry spokesman told the BBC Urdu service that Mr Ban may also announce the formation of a three-member commission to investigate Ms Bhutto's killing.
She was the victim of a gun and bomb attack as she was leaving a rally of her Pakistan People's Party (PPP) in the garrison town of Rawalpindi.
The Pakistani government and US officials have accused tribal warlord Baitullah Mehsud of plotting the attack on Ms Bhutto, although he denies the charge.
In December, a spokesman for Mr Ban said that the UN leader was optimistic that a commission into her killing could be established, but more consultations with Pakistan were needed to examine its "scope and mandate".
However the BBC's M Ilyas Khan in Islamabad says that the announcement is by no means a certainty because Mr Ban only has a short time in the country to address several pressing problems.
'Peace and stability'
In Kabul, Mr Ban pledged Afghanistan the UN's full backing ahead of elections due in August this year.
Mr Ban expressed strong UN commitment to Afghanistan
"For the United Nations, Afghanistan will be a priority in 2009," Mr Ban said at a joint news conference with President Hamid Karzai.
"I am here to demonstrate and to convey my strong commitment and support for peace and stability for... Afghanistan's people," he said.
He said there had to be improved co-ordination among Afghanistan's many international donors to maintain progress and make "tangible changes" to people's lives.
Increasing violence in the country has become a major concern for the UN and Western powers.
Mr Ban also met Nato commanders and international officials to discuss improving security.
The new US administration of President Barack Obama is trying to persuade allies to send more troops for the Nato-led operation there.
