ISLAMABAD (AFP) - Sherry Rehman, Pakistan's new ambassador to the United States, is a liberal campaigner and democracy advocate who has braved death threats in her battle to improve minority rights.

A former journalist, the 50-year-old lawmaker and confidante of President Asif Ali Zardari is one of the most prominent women and liberal politicians in a conservative Muslim country plagued by Islamic extremists.

For a time virtually confined to her house over death threats for her calls to reform blasphemy laws, she told AFP that her priority now was to improve ties with Washington that plummeted over Osama Ben Laden's killing in May.

"Our effort will be to improve relations. Both countries have interest in the region. Both countries are seeking to promote stability in the region and that should be our goal," she said.

"We have a very broad agenda with the US. We'll move ahead, keeping in view Pakistan's interest and its position on different issues.”

"Pakistan has rendered a lot of sacrifices and there are many challenges."

Close not only to Zardari, but to his wife, former prime minister Benazir Bhutto, Rehman was in the same motorcade as Bhutto when she was assassinated in a gun and suicide attack in Rawalpindi on December 27, 2007.

Educated at Smith College in the United States and Sussex University in Britain, Rehman was born in Pakistan's largest city of Karachi in 1960.

A former editor of Herald magazine, she joined the Pakistan People's Party and became spokeswoman for Bhutto, then information minister when the PPP won the 2008 elections following Bhutto's murder.

But she resigned a year later as the government dragged its feet over restoring an independent judiciary, reportedly going after failing to convince the president to lift a transmission ban on television channel Geo at the time.

Today, she is founding chairman of the Jinnah Institute, a think tank more closely aligned to the army's national security objectives than her predecessor as ambassador, Hussein Haqqani, who is deeply distrusted by the generals.

Despite her closeness to Zardari, she has stood against her party and government, at times left isolated by a leadership anxious not to inflame the religious right and prickly over its unpopularity.

In parliament, she has authorised bills seeking to empower women and outlaw domestic violence, and bills supporting journalists and a free press.

In late 2010, she sparked fury among religious groups by lodging a private member's bill seeking to abolish the death penalty for blasphemy after a Christian mother was sentenced to death.

The government and the party refused to adopt the law reforms, effectively isolating Rehman and her fellow campaigner, PPP politician Salman Taseer, who was murdered by his bodyguard in January. Two months later, Pakistan's minorities minister Shahbaz Bhatti was also killed in Islamabad.

Ali Dayan Hasan, the Pakistan director of US-based rights group Human Rights Watch, welcomed Rehman's appointment and called it the "most viable, face-saving formula for all concerned".

"She is a woman, a democrat, she is a devout liberal who has taken very brave positions in Pakistan on very contentious issues," he told AFP.

"But she is likely to be a far less threatening figure to the Pakistani military because she has greater empathy, if not sympathy, with the army's national security considerations," he added.