U.S. Defense Secretary Robert Gates urged Europe and China to step up their involvement in rebuilding Afghanistan, saying Saturday that America alone cannot put the conflict-ridden nation back on its feet while mired in a fight against the Taliban. Mr. Gates said he has been tougher on the Europeans than countries in Asia in demanding bigger contributions because three successive NATO summits have declared Afghanistan to be their highest priority.'' But he said he is concerned by the difference between the rhetorical emphasis ... and the capabilities that our allies are prepared to put forward.'' The need is greater than the commitment that has been made,'' Mr. Gates told an Asia-Pacific conference of defense ministers, officials and analysts. Afghanistan is seen as a crucial test of the power and relevance of NATO, but the escalating war in the Central Asian nation has raised doubts in Europe about the ability of the alliance's 32,000 troops to stem the Taliban insurgency. Worries about casualties and costs have contributed to opposition to the conflict that many Europeans see as an unnecessary distraction during economic crisis. The U.S. has 38,000 troops, and President Barack Obama has ordered 21,000 more be sent there. A lot of our allies are there in very large numbers ... so it's not like people have been sitting with their hands in their pockets,'' Mr. Gates said, answering questions from delegates after his speech. But to establish a sustainable and effective government in Afghanistan, the country needs additional aid and expertise to build infrastructure and more funding to expand and maintain the Afghan army, Mr. Gates said in the speech at the Shangri-La Dialogue. The annual conference is organized by the London-based International Institute for Strategic Studies think-tank. Mr. Gates also said the United States would welcome China's help in Afghanistan, whether it is for the security fund or a number of these civilian areas of expertise.'' This is one of the places in the world where all contributions are welcome,'' he said. Hundreds of U.S. experts and diplomats will be flying into Afghanistan in the months to come but that's still far short of what the need is,'' he said. It's one thing for the U.S. to be able to surge a significant number of military forces, but our civilian capabilities are limited,'' he said. The ultimate solution to Afghanistan's security is a strong national military and police force, for which the U.S. will pour billions of dollars over the next several years. Afghanistan for a considerable period of time will never be able to afford the size army and police that is required to take on the security challenges in the country,'' Mr. Gates said. Mr. Gates also praised Pakistan for stepping up the war against Islamic extremists in the region bordering Afghanistan. The Pakistani military says it has killed more than 1,100 militants in a month of heavy clashes and has the Taliban on the run in the Swat Valley region. The Pakistani establishment has come to understand that what was happening there represented a truly existential threat to the Pakistani government and Pakistani democracy,'' he said.