Barking dogs seldom bite. US President Donald Trump lived up to that idiom as he apparently did not push -- or failed to -- Chinese President Xi Jinping over North Korea as hard as he had said would.

The summit, held at a Trump resort in Florida, ended without a joint statement or news conference, although the two leaders said their talks led to progress in relations between their countries.

There seems to have been no progress, however, in their discussions on North Korea’s nuclear and missile threats, which Trump and his aides had said would be a top agenda item.

In the days leading up to Xi’s arrival in US, Trump and his aides added pressure on the Chinese side that Beijing should do its bit to rein in North Korea. Trump said that North Korea was a “humanity problem” and that the US will address it on its own if China does not help with it.

Trump did not specifically mention North Korea after the summit, and all what Secretary of State Rex Tillerson said amounted to admission of an “agreement to disagree or differ.”

He said that the two sides agreed to increase cooperation and work with the international community to convince North Korea to peacefully resolve the issue and abandon its illicit weapons programs. We heard this kind of statement from US and Chinese officials a hundred times.

In contrast to the lack of a concrete agreement on North Korea, Trump and Xi reached an accord on another key issue of their summit – trade. Secretary of Commerce Wilbur Ross said that the two sides agreed to a “100-day plan” aimed at reducing US trade deficit with China.

This raises the possibility that Trump may have used North Korea as leverage against China. Aboard his plane flying to Florida, Trump said the two issues are “mixed.”

That Trump focused more on trade than North Korea does not mean that he would ease the pressure on the Pyongyang government.

The strongest indication came from Tillerson, who said after the summit that Trump made it clear that the US is “prepared to chart our own course if this is something China is just unable to coordinate with us.”

In view of what Trump and his aides had said, it is easy to suppose the US will get much tougher in dealing with the North. They have repeatedly said every option, including military action, is on the table.

The US surprise attack on the Syrian government forces, the Trump administration’s first military action, was also a sign that Trump, when necessary, could take a more aggressive approach to security issues than his predecessor, Barack Obama.

White House press secretary Sean Spicer said that the attack punishing Syrian forces’ use of deadly chemical weapons “sends a very strong signal not just to Syria but throughout the world.”

As things stand, actions the US could take against North Korea include toughening sanctions – last week it added a North Korean trading firm and 11 individuals to its already long blacklist. Then the US could impose a secondary boycott, relist the North as a terrorism sponsoring state. In the worst case, it may consider naval blockade or preemptive strikes against key facilities in the North.

Of course, any US action against the North will depend on how North Korea – it threatened to test-fire an intercontinental ballistic missile capable of reaching the US mainland and is reported to be ready to conduct its sixth nuclear test – behaves.

Most of all, South Korea and the US should maintain close cooperation in whatever action is taken against the North. US Vice President Mike Pence plans to visit Seoul next week, and he should convince Seoul officials about the Trump administration’s commitment to resolving the North Korean problem in cooperation with US allies.