North Korea's latest underground nuclear test has prompted alarm from the immediate region and around the world.
US PRESIDENT BARACK OBAMA
North Korea will not find security and respect through threats and illegal weapons. We will work with our friends and allies to stand up to this behaviour and we will redouble our efforts toward a more robust international non-proliferation regime that all countries have responsibilities to meet.
CHINESE FOREIGN MINISTRY
Disregarding the common objections of the international community, the Democratic People's Republic of Korea has again tested a nuclear device. The Chinese government expresses its resolute opposition to this.
RUSSIAN FOREIGN MINISTRY
The latest steps by North Korea escalate tensions in north-east Asia and endanger security and stability in the region.
SOUTH KOREAN PRESIDENCY
The nuclear test is a serious threat to peace and stability on the Korean Peninsula and in north-east Asia and a serious challenge to the international regime on nuclear non-proliferation.
JAPANESE PRIME MINISTER TARO ASO
For us, it raises tensions in the region extremely.
UK PRIME MINISTER GORDON BROWN
I condemn North Korea's nuclear test in the strongest terms. This act will undermine prospects for peace on the Korean peninsula and will do nothing for North Korea's security. The international community will treat North Korea as a partner if it behaves responsibly. If it does not then it can expect only renewed isolation.
UN SECRETARY GENERAL BAN KI-MOON
I'm deeply disturbed by a report of nuclear testing. If it is confirmed, it is a clear violation of Security Council Resolution 1718 of 2006.
EUROPEAN FOREIGN POLICY CHIEF JAVIER SOLANA
These irresponsible acts by North Korea warrant a firm response by the international community.
GERMAN CHANCELLOR ANGELA MERKEL
I think it is right to have a United Nations Security Council meeting. We must do everything so that talks resume and that North Korea's independent acts come to an end. I believe that the world community should show unity here. The six-party talks were a strong signal of unity and I hope the UN Security Council succeeds in clearly showing this sign of unity towards North Korea.
AUSTRALIAN FOREIGN MINISTER STEPHEN SMITH
On the basis that North Korea has conducted a nuclear underground explosion, they deserve and get nothing other than our absolute condemnation, and that condemnation should be echoed around our region and the globe.
TIBOR TOTH, EXECUTIVE SECRETARY OF THE PREPARATORY COMMISSION FOR THE COMPREHENSIVE NUCLEAR TEST BAN TREATY
Let me call it the wrong step in the wrong direction, and if course it's up to the wider international community to make the necessary judgement. I do not want to speculate what is behind it but this is the wrong step in the wrong direction.