Chinese President Xi Jinping called for restraint in dealing with North Korea during a telephone call with U.S. President Donald Trump, Chinese state media reported Monday, amid speculation that the North could soon carry out a sixth nuclear test.

State broadcaster CCTV quoted Xi as telling Trump that China strongly opposes North Korea's nuclear weapons program, which violates United Nations Security Council resolutions, and hopes "all parties will exercise restraint and avoid aggravating the situation" on the Korean Peninsula.

The Trump administration has warned that all options, including a military strike, are on the table to stop North Korea from developing a nuclear-tipped missile that could reach the U.S. mainland. However, U.S. officials have told The Associated Press that a military response isn't likely. Trump has reportedly settled on a strategy that emphasizes increasing pressure on North Korea with the help of China.

"Only if all sides bear the responsibilities they're supposed to bear and come together, can the nuclear issue on the peninsula be resolved as quickly as possible," Xi told Trump, according to CCTV.

The phone call, which took place Monday morning Beijing time, came as South Korean officials warned there is a chance that North Korea will conduct a nuclear test or a maiden intercontinental missile launch around the founding anniversary of its military on Tuesday.

Trump has pressed Xi to exert greater pressure on North Korea, given China's status as the country's economic lifeline and sole major ally. Monday's call is the second time that the two leaders have spoken by telephone since meeting in Florida earlier this month.

In an interview Friday at the Oval Office, Trump told the AP that he declined to label China a currency manipulator mostly because he needed Xi's help with the North Korean crisis.

"They are working with us on North Korea. Now maybe that'll work out or maybe it won't," Trump said, adding that he had a "great relationship" with the Chinese president.

Trump also spoke Monday with Japanese Prime Minister Shinzo Abe, and they agreed to urge North Korea to refrain from what Abe called provocative actions.