North Korea will be the key US concern when top diplomatic and defence officials from the United States and China meet in Washington for the Diplomatic and Security Dialogue starting today.

The dialogue, decided by President Donald Trump and President Xi Jinping in April, is more narrowly focused on key security issues than previous dialogues.

Secretary of State Rex Tillerson and Defence Secretary James Mattis will be meeting China's State Councillor Yang Jiechi and Chief of the General Staff of the People's Liberation Army Fang Fenghui.

"Specifically, we are going to give the DPRK/North Korea issue top priority," Ms Susan Thornton, Acting Assistant Secretary of State for East Asian and Pacific affairs, told reporters on Monday.

The US is trying to create a "global echo chamber" where all countries get behind the United Nations Security Council resolutions that address North Korea's illicit weapons programmes, she said.

There had been "notable cooperation" from China, she said, citing its ban on North Korean coal imports. "But we would like to see China do more," she said.

In Beijing yesterday, Foreign Ministry spokesman Geng Shuang said: "We hope the concerned parties will… meet each other halfway and properly handle and resolve the nuclear issue. China is willing to work with the US and other concerned parties to maintain communications and cooperation."

The nationalist tabloid Global Times this week weighed in, writing: "Solving the North Korea nuclear issue requires joint efforts from China and the US... It is an illusion that the issue can be resolved solely through China's help."

Territorial disputes in the South China Sea will also figure in the talks, with the US wanting a freeze on all building activity in the area.

Mr Geng said: "Through the joint efforts of China and Asean, the South China Sea situation has stabilised, and the South China Sea issue has returned to the right track of negotiation and peaceful resolution. We hope concerned parties can respect efforts by regional countries to resolve the disputes peacefully through negotiation."

The US also wants China to take a higher profile in the fight against terror and the Islamic State in Iraq and Syria (ISIS), said Ms Thornton.

Earlier this month, Beijing said it was "gravely concerned" about a claim by ISIS to have killed two Chinese teachers in Balochistan province in Pakistan, where China is working with Islamabad on a US$55 billion (S$76 billion) infrastructure project.

Referring to North Korea's nuclear programme, Professor Shi Yinhong of Renmin University told The Straits Times: "China will make some concessions, but it is doubtful that China can do much."

Ms Thornton said: "We want to have a very constructive and results-oriented relationship with China." A second round of the dialogue will be held later this year.