WASHINGTON - President Asif Ali Zardari is expected to face some pressure during the upcoming talks here with U.S. President Barack Obanma to work with PML-N Quaid Nawaz Sharif in an effort to strengthen his civilian government in combating the Taliban challenge, according to informed sources. Zardari, who arrives Monday evening from London for a week-long visit to the United States, is set to hold a series of meetings with the American leadership as well as attend the trilateral summit President Obama is hosting with his Pakistani and Afghan counterparts on Wednesday amid growing US concern over the deteriorating situation in the region. Afghan President Hamid Karzai and Zardari will also hold separate talks with Obama as well as a mini-summit, White House spokesman Robert Gibbs said Friday. "The president looks forward to discussing with these two democratically elected leaders how we can work together to enhance our cooperation in this important part of the world as the United States implements a new strategy" for Afghanistan and Pakistan, said Gibbs. Diplomatic observers said that during his meeting with Obama later this week, the controversial deal Pakistan made with the Taliban is also expected to come up. The US and other critics have cast the peace deal as a surrender. American officials say they worry that the Swat district will become a haven for militants near Afghanistan, where U.S. and NATO troops are battling an increasingly virulent insurgency. But on Sunday, US Defence Secretary Robert Gates said that the Pakistan Amy was regaining the initiative against the Taliban. Pakistan, meanwhile, is forging ahead with its end of the deal. Pakistani officials say by carrying out their part of the agreement they can gain more support from the public to take action against the Taliban if and when the militants violate the pact. Ahead of President Zardari's visit, President Obama said the government in Pakistan is very fragile and expressed concern about security in the nuclear-armed nation, as Pakistani forces battled Taliban militants in the northwest. The government doesnt seem to have the capacity to deliver basic services: schools, health care, rule of law and a judicial system that works for the majority of the people, Obama said at a White House news conference Wednesday night. The US has huge national security interests in making sure that Pakistan is stable and that you dont end up having a nuclear-armed militant state, Obama told reporters. Obama has made tackling extremism in Pakistan and neighbouring Afghanistan the central focus of U.S. foreign policy and is pressing the government in Islamabad to crack down on militants. The Obama administration has criticized the peace accord that saw Islamic law introduced in seven northwestern districts, including Swat, Buner and Dir, and last week accused the government of abdicating to extremists. US officials are supportive of the Pakistan Army offensive and asked Congress to approve $400 million to shore up the fight against extremists. The Pakistani government is undertaking concrete actions to demonstrate their commitment to counterinsurgency and counterterrorism, Undersecretary of Defense Michele Flournoy told the House Armed Services Committee in Washington. We must show our Pakistan partners that if they take decisive action against extremists, we will give them the support they need. The $400 million, requested earlier this month, would expand U.S. training and equipment for Pakistani forces to conduct counterinsurgency operations. Still the Obama administration perceives the Zardari government as weak, with unnamed American officials saying their confidence in it was waning. In a recent dispatch The New York Times said there was heightened concern in the Obama administration about the survivability of the Zardari government. Gen. David Petraeus, the head of the United States Central Command, has said in private meetings in Washington that Pakistan's government is increasingly vulnerable, the newspaper said. No one here is publicly saying that the Obama administration is trying to work out a power-sharing deal between Zardari and Nawaz sharif. Official point out that both Special Envoy Richard Holbrooke and Secretary of State Hillary Clinton have spoken with Nawaz Sharif by telephone in the past month, and have urged Zardari's "increasingly unpopular government" to work closely with Sharif.