The administration of US President Barack Obama is reaching out to former Pakistani prime minister Nawaz Sharif, the chief rival of President Asif Ali Zardari, in hopes to find a way to strengthen the country's government, The New York Times reported late Friday. Sharif, who served as Pakistan's prime minister twice during the 1990s, represents the Pakistan Muslim League-N. Citing unnamed administration officials, the newspaper said on its website that because of his ties to Islamists, the US government has long held Sharif at arms length. But now some Obama administration officials say those ties could be useful in helping Zardaris government to confront the challenge from Taliban insurgents, the report said. The Pakistani government ceded control of the nearby Swat valley to Islamists in February, signing a deal to allow religious hardliners to enforce Islamic law in the region in order to end a bloody two-year rebellion led by a radical cleric. But instead of disarming as required under the deal, the Taliban instead pushed further south towards Islamabad, taking over large swathes of Lower Dir and Buner. According to the paper, the US move reflects heightened concern in the Obama administration about the survivability of the Zardari government. The head of the United States Central Command, General David Petraeus, has said in private meetings in Washington that the Pakistani government is increasingly vulnerable, The Times said. No one in the administration is trying to broker an actual power-sharing agreement between Zardari and Sharif, the paper noted. But administration officials say Secretary of State Hillary Clinton and Richard Holbrooke, the special representative for Afghanistan and Pakistan, have both urged Zardari and Sharif to look for ways to work together, The Times said.