President Lee Myung-bak and Kazakh President Nursultan Nazarbayev agreed Monday to continue to cooperate closely to ensure various economic projects between the two countries go ahead smoothly, the presidential office said.

As part of the efforts, the two leaders agreed to conclude a temporary labor pact at an early date that will help South Korean people to do business in the Central Asian nation under fewer restrictions, the office said in a statement.

On the sidelines of the summit, the two countries also signed a memorandum of understanding on a joint project to minimize the loss of electricity in the course of transmission and distribution in Kazakhstan, the statement said.

Nazarbayev is one of more than 50 world leaders who have gathered in Seoul to attend the Nuclear Security Summit that is opening later Monday. The conference is aimed mainly at discussing ways to keep nuclear material away from the hands of terrorist groups.

Lee and Nazarbayev, who have built a close friendship while holding summit talks with the Kazakh leader every year since Lee took office in 2008, expressed satisfaction that the strategic partnership between the two countries has substantially moved forward, the office said.

Lee expressed gratitude for Kazakhstan's support for Seoul's efforts to make the nuclear conference a success, praising the country for trying to help produce a better outcome from the gathering, especially on the issue of nuclear material disposal, it said.

Nazarbayev spoke highly of Seoul's preparations for the global conference, it said.

Presidential spokesman Park Jeong-ha said the two leaders shared common concerns that North Korea is too closed off from the outside world, and that its people are suffering and its economy cannot move forward.

Nazarbayev stressed that nuclear states should show "good will"

and called for discussions at the United Nations or other forums to establish a reward system for countries that give up nuclear weapons, the spokesman said.

Kazakhstan is one of the nations that voluntarily abandoned its atomic weapons.

Lee said the international community should speak to North Korea with one voice, Park said.

Nazarbayev offered a basket of chocolate and fruit as a birthday present for South Korean first lady Kim Yoon-ok, the spokesman said. Kim turned 65 on Monday. (Yonhap News)