Britain's Foreign Office said Friday that talks planned for next week to discuss hardening sanctions over Iran's nuclear program have been postponed, and officials were trying to set a new date. A European Union official, speaking on condition of anonymity, said the Chinese could not attend due to scheduling problems. China, along with Russia, is opposed to a hardening of sanctions against Teheran. "Negotiations will be taking place over the next few days" to set a new date for a meeting, said a Foreign Office spokesman, on condition of anonymity in line with policy. Talks between political directors of the five permanent members of the United Nations Security Council and Germany were planned for Monday, and had been expected to take place in Brussels.