Leaders of the Shanghai Cooperation Organization (SCO) on Tuesday pledged greater unity, increased economic cooperation and a firmer resolve to combat terrorism.

In both the declaration and the joint-communiqu issued at the end of the two-day summit, the heads of the SCO member states - China, Kazakhstan, Kyrgyzstan, Russia, Tajikistan and Uzbekistan - also reached consensus to counter new challenges, which range from the global financial crisis, energy and food security to climate change.

The leaders delved into major security issues that brought the six countries together eight years ago with the leaders of four observer states - Mongolia, Pakistan, Iran and India - as well as Afghan President Hamid Karzai, the special guest of Russian President Dmitry Medvedev in attendance.

In their declaration, the leaders reaffirmed that the Nuclear Non-Proliferation Treaty (NPT) is the international foundation for preventing the spread of nuclear weapons.

The SCO reiterated its strong support for the NPT and welcomed multilateral efforts to strengthen it on the basis of non-proliferation, disarmament and peaceful use of atomic energy.

They signed the Convention against Terrorism, which strengthens the legal counter-terrorism framework within the SCO to combat terrorism, separatism and extremism as well as drug trafficking and cross-border organized crime.

They agreed that last month's underground nuclear test by the Democratic People's Republic of Korea was "absolutely unacceptable", Medvedev told a press conference on Tuesday soon after the summit ended.

In Afghanistan, there should be a comprehensive approach, including political, security and economic measures, President Hu Jintao said in his speech during the plenary session, adding that the SCO should act on members' consensus in controlling money laundering and safeguarding energy transportation pipelines.

The leaders also touched upon public health issues, taking note of the serious health risks such as the H1N1 flu pandemic, Medvedev said.

The pressing need for deepened economic cooperation for growth and faster recovery from the economic downturn was high on the agenda at the SCO summit. The leaders agreed to upgrade the SCO's Business Council and Inter-Bank Union from a mainly bilateral to a multilateral sphere so that the member states can better coordinate financial and monetary policies to push for growth and faster economic recovery.