Mr Trump lately expressed impatience over China's role in North Korea, particularly after Pyongyang launched an intercontinental ballistic missile last week that some experts believe could reach Alaska and parts of the US West Coast.
Intercontinental ballistic missiles (ICBMs) are those that travel at a velocity of anywhere from five to 10 kilometres per second and at a distance of at least 5,000 miles. "This time, the bombers carried out a firing drill, which is unusual".
China's United Nations ambassador, Liu Jieyi, told the Security Council meeting that the missile launch was a "flagrant violation" of United Nations resolutions and "unacceptable".
There has always been a crisis atmosphere between North Korea and the South and the United States.
"North Korea's actions are a threat to our allies, partners and homeland", Gen. Terrence O' Shaughnessy, the Pacific Air Forces commander, said.
During his meeting with Trump, Xi noted that the two sides are discussing a one-year cooperation plan, and that the 100-day economic cooperation action plan initiated after the meeting with Trump at Mar-a-Largo in April has made new progress.
"Ultimately North Korea still wants Korean unification on their terms", Bennett said.
Pyongyang was heavily criticised after launching the missile.
Trump, who left the G20 meeting without giving a press conference, claimed in a tweet that he had just finished "an excellent meeting on trade and North Korea" with Xi.
Moon also appears to have sublimated whatever opposition he had to THAAD, Terminal High Altitude Area Defense.
"The global community can cut off the major sources of hard currency to the North Korean regime".
Although the North has now shown it can reach USA soil, it probably isn't capable yet of arming such a missile with a nuclear warhead. However, here again, his bullying rhetoric towards China on Twitter is simply inappropriate.
"The current situation where there is no contact between the relevant officials of the South and the North is highly unsafe", Moon said.
"Our self-restraint holds, and diplomatic efforts remain underway as we speak, " he said, adding, however, that diplomatic and economic efforts remained the tools of choice to convince North Korea to stop its nuclear and missile programmes. It also accused a Chinese bank of laundering money for Pyongyang.
China is key to achieving the hard goal of making North Korea change its path. A conflict on the Korean peninsula would destabilise not only the region, but the whole world, and is in nobody's interest.
That response ran counter to what China and Russian Federation had hoped the United States would do.
The President even suggested earlier this year that he was holding fire on China - by not labeling them a currency manipulator - due to their work on North Korea.
Mattis spoke by phone with South Korean Defence Minister Han Min-koo on Thursday, reaffirming Washington's commitment to the US-South Korea alliance and promising "the full range of US capabilities".
United States analysts monitoring the communist nation believe it could conduct another nuclear test "at any time". Moscow has adamantly stated that new sanctions will only lead to a stalemate. Issues that Japanese leaders still would like to be resolved despite the military movement of North Korea. With a population of more than 20 million, Seoul is in easy range of North Korea's massive array of artillery guns north of the Demilitarized Zone that forms a buffer between North and South. Japan could also be a target.