Leaders of more than 50 countries and international organizations gather in The Hague on Monday for a summit aimed at boosting global cooperation on nuclear security.

The two-day international event is of great importance against the background of a world that remains haunted by the specter of nuclear proliferation and even nuclear terrorism.

The previous two Nuclear Security Summits, respectively held in Washington and Seoul, generated a broad consensus and a series of measures on maintaining nuclear security and combating nuclear terrorism.

Much headway has been made since, but much more needs to be done. As nuclear power flourishes and relevant technology spreads around the world, nuclear-related risks such as accidents, sabotage and proliferation still lurk around every bend.

Figures from the International Atomic Energy Agency, the world's nuclear watchdog, show that more than 100 cases of loss or theft of radioactive substances are reported every year.

Japan also serves as a reminder. Regardless of its location in one of the most seismically active areas in the world, and in defiance of international norms, Tokyo was reluctant to return to the United States a large stockpile of highly enriched uranium and weapons-grade plutonium.

The attitude is particularly worrisome in light of the world-shocking, long-lingering Japanese nuclear disaster triggered by the March 2011 great earthquake and tsunami.

Given the challenging situation, it is high time that a more efficient and effective mechanism be put in place to boost international coordination and cooperation to safeguard nuclear security across the world.

Those countries that own nuclear materials should shoulder the responsibility of protecting them, especially preventing them from falling into wrong hands.

Meanwhile, those countries with relatively mature experience in safeguarding nuclear security need to be more generous and forthcoming in sharing their expertise.

Due to the unique characteristics of nuclear materials and weapons, nuclear threats are by no means confined to national borders. Only through a combination of national and international genuine efforts can the world effectively maintain global nuclear security.