WASHINGTON - The United States has called for "active cooperation and communication" between Pakistan and Afghanistan to combat terrorism on their border as tensions rose between the two neighbouring countries following Afghan President Hamid Karzai threat to go after the militants inside the Pakistani territory. A State Department spokesman, who faced questions on Karzai's weekend tough talk, reiterated the US support for efforts towards 'enforceable and comprehensive' solution to deal with resurgence of militant act. "We continue to believe that active cooperation and communication between Afghanistan and Pakistan officials is indispensable to focus efforts on defeating our common enemies," spokesman Gonzalo Gallegos added. But experts and analysts doubt whether a weak leader like Karzai could have made adopted that hostile stance towards Pakistan without a wink and a nod from Washington. Over the weekend, he threatened to send Afghan troops to pursue militants into Pakistani territory. Pakistan has reacted strongly to his threats, summoning Kabul's envoy to lodge a protest and making it clear that "the only way to win the war against terrorism and extremism is by showing full respect to territorial sovereignty and non-interference in each other's internal affairs." On Monday, US President, during a press conference in London, also offered help in cooperative efforts to overcome extremism challenges in the border region. At the State Department, the spokesman cited Bush's remarks and told journalists at the daily briefing that "the most important thing is that the - all sides, including the United States, become more involved, that we bring the sides together to help them to communicate better, to know and understand the danger that is posed there, and to coordinate and communicate in that - in a much clearer way." He stated that leaders on both sides understand that cross-border infiltration must be stopped. "Taliban and other insurgent elements are a threat to both Afghanistan and Pakistan and cross-border infiltration must be stopped. Both countries understand that. Any solution must seek to deny the extremists access to the border region. To render these areas inhospitable to terrorists and violent extremists, solutions must be enforceable, comprehensive, and promote sustainable development throughout the region. And we continue to work with both governments to help them with that." The spokesman said consultation and dialogues, such as continuing the fruitful Jirga process begun last August, can bring great benefits to both countries and the United States. Meanwhile, at UN Headquarters in New York, the Security Council has welcomed the renewed commitment expressed by more than 80 countries and international organisations last week in Paris to advance peace, security and development in Afghanistan. The International Conference in Support of Afghanistan, held on 12 June, saw fresh pledges of resources for the country's rebuilding efforts, as well as the launch of the government's five-year plan to reduce poverty and promote economic and social development, known as the Afghan National Development Strategy (ANDS). The meeting, co-chaired by Afghanistan, France and Secretary-General Ban Ki-moon, concluded with the adoption of a declaration in which participants voiced their support for the strategy which they said "will be our road map for joint action over the next five years and sets our shared priorities." In a statement read out to the press by Ambassador Zalmay Khalilzad of the United States, which holds the rotating presidency of the Council for this month, the 15-member body "welcomed the reaffirmation of the long-term partnership between Afghanistan and the international community, the aim of which is to give the people of Afghanistan a better future, including in terms of security, prosperity and human rights." The Council also welcomed the commitment of participants to support the ANDS, "including by making generous and unprecedented financial pledges, which demonstrated continuing international resolve," as well as the Government's commitment to pursue political and economic reform, to work with the international community and to take leadership for its development. At the same time, the Council stressed the need to continue to address the threat to the country's security and stability posed by the Taliban.