 U.S. Secretary of State John Kerry gave his response to Iran's pledge to stop developing nuclear weapons and engage with the West in Davos today. Speaking in the same conference hall, Iran's president appeared in early in the week. He said what was needed now from Iran was action. Now, yesterday President Rouhani stood here, and he said that Iran is eager to engage with the world, and hopefully. But Iran knows what it must do to make that happen. He told you that Iran has no intention of building a nuclear weapon. Well, while the message is welcome, my friends, the words themselves are meaningless unless actions are taken to give them meaning. John Kerry also refuted suggestions that U.S. diplomacy was disengaging from the world and particularly the Middle East. We will defend our partners and our allies as necessary, and we will continue to ensure the flea flow of energy, dismantle terrorist networks, and we will not tolerate the proliferation of nuclear weapons. The theme of nuclear weapons was picked up by Iran's foreign minister, speaking here in a session on the Middle East. If Iran agrees with the West on the nuclear issue, then it should remove a concern that Iran will never produce a nuclear weapon. Why is it that some countries in the region are concerned? There are problems in the region. We have governance problems in the region. We have confidence deficits in the region. We need to address them. We have a mentality in the region that considers the problems of one group or one country as its asset. And Turkey's foreign minister underlined that nuclear weapons should not be an option. There should not be any nuclear power in our region, neither in Iran nor in any other country. Secondly, there should not be any limitation on developing nuclear technology as a source of energy. Elsewhere, climate change continues to be a much discussed issue in the corridors of Davos. Campaigner Al Gore says it's an issue where real progress is being made. We can solve it, but it will take the commitment of the kinds of people that come here regularly. And this year convinces me we are genuinely close to the political tipping point we've been searching for and waiting for. The World Economic Forum annual meeting enters its final day in Davos with sessions on rebuilding banking and the global agenda for 2014.