The wire fence being constructed on the border between China and the Democratic People's Republic of Korea has nothing to do with the recent nuclear test by the DPRK, said Chinese Foreign Ministry spokesman Liu Jianchao on Tuesday.

"China has been building border-control facilities since the 1990s and no link should be made to the current situation on the Korean peninsular," he told a regular press conference.

He clarified that China has been constructing wire fences and patrol roads on its land borders, including the China-DPRK border, since 1990.

"The aim of these facilities is to improve management and control of the borders," he said, calling the construction "a normal act".

China calls for Japan to stick to non-nuclear principles

China on Tuesday called for Japan to stick to its "Three Non-Nuclear Principles" and take a responsible attitude to safeguarding regional peace and stability.

Chinese Foreign Ministry spokesman Liu Jianchao made the remarks at a regular press briefing in response to a question concerning the suggestion by some Japanese politicians that Japan should develop its nuclear weapons, following the nuclear test by the Democratic People's Republic of Korea (DPRK).

"We hope Japan, as a signatory of the Treaty on the Non-Proliferation of Nuclear Weapons, will strictly carry out its obligations and stick to the Three Non-Nuclear Principles," Liu said.

The principles, approved in 1971, state that Japan will not produce, possess or allow nuclear weapons on its territory.

Japanese Prime Minister Shinzo Abe said last Tuesday that Japan would stick to its "Three Non-Nuclear Principles" and was not planning to possess nuclear weapons.

North Korea: Sanctions 'declaration of war'

SEOUL, South Korea - North Korea said Tuesday the United Nations effectively declared war on the country when it imposed sanctions for the North's nuclear test. [Full coverage on N.Korea nuclear crisis]  

North Korea wants "peace but is not afraid of war," the North's Foreign Ministry said in a statement carried by the official Korean Central News Agency.

The UN Security Council "resolution cannot be construed otherwise than a declaration of a war," the ministry said, calling the sanctions "a product of the US hostile policy toward" North Korea.

The ministry warned that if anyone used the U.N. resolution to infringe on the country's sovereignty, North Korea "will deal merciless blows at him through strong actions."

The UN sanctions, approved Saturday, bans the sale of major arms to the North and orders the inspection of cargo to and from the country. It also calls for the freezing of assets of business supplying the North's nuclear and ballistic weapons programs.

The North "will closely follow the future US attitude and take corresponding measures," the statement said, without specifying what those measures would be.

The United States began a new round of diplomacy in Asia to address divisions over how to impose the sanctions, with Secretary of State Condoleezza Rice to arrive in Japan on Wednesday before traveling to South Korea and China. The US announced that air samples gathered last week contain radioactive materials confirming that North Korea conducted an underground nuclear explosion, as it claimed.

The sanctions ban trade with the North in major weapons and materials that could be used in its ballistic missile and weapons of mass destruction programs. They call for all countries to inspect cargo to and from North Korea to enforce the prohibition, "as necessary," and consistent with each nation's laws.

North Korea's No. 2 ranking leader, Kim Yong Nam, defiantly said the country would strengthen its military and "achieve a final victory in the historic standoff with the US"