The country's deputy foreign minister says she was very disappointed that no deal was reached at last month's summit between President Trump and Kim Jong Un, and blamed the breakdown of talks on the U.S., accusing American diplomats of being too demanding and stubborn.

Earlier this week, the U.S. special representatives for North Korea said Washington would not accept a phased denuclearization of the country.

He also insisted that the two countries are still in communication despite the failure of last month's talks.