WASHINGTON (Reuters/AFP) - US Secretary of State Hillary Clinton said on Friday she expected intense sessions when the presidents of Afghanistan and Pakistan come to Washington for three-nation talks next week. The top US diplomat listed the key challenges as bringing peace and stability to Afghanistan, Pakistan and Iraq as well as charting the best course forward in the Middle East and dealing with Irans nuclear ambitions. President Barack Obama is due to meet Pakistani President Asif Ali Zardari and Afghan President Hamid Karzai on Wednesday and Thursday, the second in a series of planned trilateral meetings aimed at improving coordination and strategy to stabilize both countries. Hillary, who did not offer specifics, said the meetings were useful to change mindsets and put forward what Washington wanted both sides to do. The last meeting was in February when Hillary announced the two had agreed to hold regular three-nation talks on strategy in their war in South Asia. Well have some very intense sessions on the specifics of what were trying to accomplish, Hillary said of next weeks meetings. The Obama Administration wants Pakistan to do more to fight home-grown militants that pose a threat to neighbouring Afghanistan, where the US along with allies is trying to rout the Taliban. In Pakistan, its a very difficult environment because of the confusion among the civilian and military leadership about how to prioritise what is the greatest threat to Pakistan going forward, said Hillary. We have worked to reset our relationship, even though we didnt spell reset right in Russian, she said, stirring laughter. We have actually thought back on that as a moment of levity which may well have increased their willingness to cooperate with us, Hillary told foreign service officers who recalled her arrival for work at the State Department on January 22, two days after President Barack Obama took office. During her speech, Hillary appeared congested but State Department spokesman Robert Wood told reporters she suffers from mild allergies. Thats all it is. Hillary Clinton, marking 100 days as chief US diplomat, said she is heartened by a positive response to the new US foreign policy and joked that a gaffe with Russia may end up boosting ties. This is my 100th day serving as secretary of state, she said. Weve reinforced our relationships with key allies and historic partners in Europe and Asia, she said. Meanwhile, the US on Friday denied having set a 'two-week time frame for Pakistan to take action against Taliban operating in the country, but said the military offensive by the army has to be consistent and decisive. I dont know where this two-week timeframe came from, but look, we have said very clearly that we believe the Pakistanis need to take action against these extremist elements, State Department spokesman Robert Wood told reporters at his daily press briefing. The Fox News had earlier reported that General David Petraeus, Commander of US Central Command, told US lawmakers that coming two weeks are going to be very critical to determining whether the Pakistani government will survive. Robert Wood said action against the Taliban and extremist elements is not something that can be put in a timeline in terms of taking action. It has to be consistent, decisive, and we need to understand that this is not something were going to be able to deal within two days, two weeks, two months, he said. This is going to take time. But whats important is, as I said the other day, 110 per cent effort. And Pakistan seems willing to go in that direction. Well continue to try to help them if they move in that direction, Wood said. The State Department said the US will be working with Pakistan and provide assistance to it along with other countries who believe it is critical to international security to defeat the Taliban and the extremists that are operating in Pakistan and Afghanistan. Pakistan is doing this out in its own national security interests... Its important that these extremists be dealt with, and were going to continue, as I said, to work with them and others, Wood said. The spokesman termed positive the action taken by Pakistan Army in the last couple of days. But said, the US was under no illusions. Its going to take more than two days worth of action. Its going to take consistent, determined, and forceful action, he said.