China and the United States should handle unresolved disputes in a constructive manner to avoid misunderstanding and escalation in conflicts, President Xi Jinping told US President Barack Obama on Thursday.

China will firmly safeguard its sovereignty and relevant rights over the South China Sea, and it will not accept any activities in the excuse of free navigation that could harm national sovereignty and interests, Xi said.

"I would like to reiterate to work together with the US side to establish a new-type relationship of big powers, achieve the goal of no conflicts or confrontations, respect with each other, cooperate for win-win results, which is the priority of China's foreign policy," he said.

The Chinese president made the remarks while meeting with Obama on Thursday afternoon on the sidelines of the fourth Nuclear Security Summit (NSS) in Washington on Thursday and Friday.

The 90-minute meeting was the only bilateral meeting that Obama has arranged during the summit attended by more than 50 heads of state and government. Obama did have a trilateral meeting in the morning with Japanese Prime Minister Shinzo Abe and Republic of Korea President Park Geun-hye.

Xi acknowledged that there are disputes and different views between China and the US in some areas, and both sides should respect each other's major concerns and seek solutions through dialogue.

"I expect to enhance communications with President Obama to focus on cooperation, manage disputes, boost mutual trust and push forward the China-US relationship to continue to develop in a healthy and stable direction," he said.

China would like to enhance communications with the US on regional and global issues such as the nuclear issue of the Korean Peninsula, said Xi, who arrived in Washington on Wednesday evening after a three-day visit to the Czech Republic.

As the world's biggest developing country and developed nation, China and the US have important responsibilities in maintaining world peace and safeguarding stability, and there is large room for the two countries to cooperate, Xi said.

Xi mentioned that the bilateral trade, two-way investment and personnel exchanges between China and the US have reached the highest level during the past few years.

The two countries have carried out effective communications on issues including Iran's nuclear program, Syria, Afghanistan, peacekeeping, development and health, showing that there is great potential for the establishment of a new-type big power relationship between China and US, Xi said.

The global economy is experiencing a sluggish period, and all the countries around the world should not stimulate exports by currency depreciation, he added.

China and the US should improve the mechanism for boosting military mutual trust, and the two countries should make the issue of cybersecurity an area for China-US cooperation, Xi said.

Cyber security was a contentious issue between the two countries for years before Xi's state visit to the US last September, when the two leaders reached a consensus to more effectively tackle the issue.

The Chinese president also reiterated China's stance on Taiwan, and he called on the US to uphold the One-China policy and maintain the peaceful development of Cross-Straits ties.

Obama reiterated that the US welcomes the rise of a peaceful, stable, and prosperous China, working with the US to address global challenges.

He praised the cooperation between the two countries in nuclear security, citing the example of China's new Nuclear Security Center of Excellence, a joint program between the two nations.

"I believe we can deepen our cooperation, including against nuclear smuggling," he said.