U.S. President Joe Biden says his country seeks "serious and sustained diplomacy" with North Korea for the complete denuclearization of the Korean Peninsula.

In his first address of the UN General Assembly on Tuesday, the U.S. leader made no mention of the recent missile launches by North Korea. 

Instead, Biden said Washington seeks concrete progress toward an available plan with tangible commitments that would increase stability on the peninsula and in the region, as well as improve the lives of the people in the North.

Biden did not explicitly name China in his speech, but stressed that his country is shifting its focus to the Indo-Pacific region, vowing close cooperation with its allies and partners.

Biden explained that the U.S. is “not seeking a new Cold War, or a world divided into rigid blocs", and is ready to work with any nation even if they have intense disagreements. But he added it will oppose attempts by stronger countries to dominate weaker ones.

Chinese President Xi Jinping also issued an indirect criticism of the U.S.' foreign policy in his UN speech -- that a country cannot judge other countries and democracy is not an exclusive privilege of certain countries.