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.

Obama said he and Xi are both committed to the denuclearization of the Korean Peninsula and the full implementation of the UN sanctions.

He praised the new steps the two countries announced on Thursday to accelerate implementation of the Paris Agreement.

In a joint statement on climate change, the two countries said they will both sign the Paris Agreement on April 22 and take necessary domestic steps to implement it as soon as possible.

"And I have been committed throughout my administration to working effectively with China on a whole range of issues and have developed a frank and effective level of communications cooperation with President Xi as we seek to expand cooperation between our countries and narrow our differences," Obama said.

He expressed concerns over issues including cybersecurity, human rights, maritime and intellectual property protection. He said he appreciated that Xi has held candid conversations in a constructive manner with him on these issues.

Obama also expressed wishes for a successful G20 summit in September in Hangzhou, East China's Zhejiang province.

In a press briefing afterward, China's?Vice Foreign Minister Zheng Zeguang described the meeting as "positive, constructive and fruitful".

Ted Carpenter, senior fellow of defense and foreign policy at Cato Institute, said there needs to be serious discussions about developing some "rules of the road" in the South China Sea.

"Only preliminary steps can be taken now, but the current trend toward a dangerously confrontational stance by both countries can be halted and even reversed," he said.

Many in China regard the US as biased in handling the maritime territorial disputes between China and some of China's neighbors, including some US treaty allies.

Xi and Obama last met in Washington in September during Xi's state visit to the US, and then met Nov 30 in Paris at the climate conference. They also had three phone calls since then and are expected to meet at the G20 summit in China in September.

Zeng said both leaders said they are looking forward to meeting in Hangzhou.

China replaced Canada last year as the US' top trade partner. The two largest economies have greatly expanded their cooperation the last few years, such as in military-to-military exchanges, non-proliferation leading to the P5+1 Iran nuclear deal and in the training of young diplomats in Afghanistan.

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