The United States should have multiple engagement with the Democratic People's Republic of Korea(DPRK) rather than continuing its sanctions against the country, said a latest study that was released?in Washington?on Thursday.

"Sanctions alone cannot provide protection from the threat posed now or in the future by North Korea. Instead, economic engagement starts a process that may lead to significant benefits without enhancing the DPRK's military capabilities or making the US or its allies more vulnerable," said the study by experts from the Asia Society and the University of California.

"Encouraging a more open and market-friendly economic growth strategy would benefit the North Korean people as a whole and would generate vested interests in continued reform and opening, and a less confrontational foreign policy," the study noted.

Apart from economic engagement, the United States should also expand its academic exchanges with the DPRK, while US aid and development groups should be encouraged to work there, and the United States should give up the policy that forbids Pyongyang's entry into the International Monetary Fund and other international financial institutions, the study suggested.

Prior to the release of the study, Secretary of State Hillary R. Clinton said here on Wednesday that the Obama administration will not have normal ties with the DPRK or relax its sanctions against the country until Pyongyang abandons nuclear arms.

"Its (DPRK) leaders should be under no illusion that the United States will ever have normal, sanctions-free relations with a nuclear-armed North Korea," Clinton said in her policy address to the United States Institutes of Peace.

The United States has been urging the DPRK to give up nuclear arms for years. Although it agrees to be open to have dialogue with Pyongyang, the Obama administration insists that Pyongyang must agree to return to the six-party talks.

Any of US bilateral contacts with the DPRK should lead to the resumption of six-party nuclear disarmament talks, Kurt Campbell, assistant secretary of state for East Asia, said at the Council on Foreign Relations on Tuesday.