(CNN) At the end of June, US President Donald Trump appeared to have deals in hand with North Korea and China that would have put nuclear and trade talks back on track.

What a difference a month makes.

Since Trump met with North Korean leader Kim Jong Un and became the first sitting US president to set foot on North Korean territory, Pyongyang has test-fired sophisticated weaponry three times in eight days . And since Trump and Chinese President Xi Jinping met at the G20 leaders summit in Osaka, Japan for trade talks, the White House has said it would enact an additional 10% tariff on $300 billion worth of products coming from China -- including consumer electronics like iPhones, sneakers and toys. The move means effectively all goods coming in from China will now be taxed.

To top it off, Washington's two allies in the region -- South Korea and Japan -- are in the middle of a feud that's reached fever pitch, with Tokyo removing Seoul from a list of countries it can trade with with limited restrictions.

China

When Trump emerged from his meeting with Xi in Osaka in June, he said trade talks were "right back on track."

He then told reporters at a news conference that although the US wouldn't be lifting current tariffs, Washington also wouldn't tax what he called the "$350 billion left that could be tariffed."

"We're not going to be doing that," he said.

On Thursday, shortly after the latest round of US-China trade talks in Shanghai ended, Trump tweeted that contrary to his earlier announcement, the US would place an additional tariff of 10% on the remaining $300 billion of products coming from China, beginning September 1.

An administration official familiar with the matter said Trump wasn't pleased that Beijing had not offered concrete promises to purchase American agricultural products during the Shanghai talks. Trump had believed he and Xi had agreed to that during their G20 meeting.

"He (Xi) said he was going to be buying from our farmers; he didn't do that. He said he was going to stop fentanyl from coming into our country -- it's all coming out of China; he didn't do that," Trump told reporters Thursday when asked about the new tariffs.

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By enacting the new measures, Trump is escalating the trade war significantly and effectively ending the truce he and Xi agreed to in June, said Rajiv Biswas, the Asia-Pacific chief economist at IHS Markit.

Craig Allen, the president of the US-China Business Council, said the move appears to be "very counterproductive."

"The interpretations of the meeting 24 hours ago were positive. It was a successful meeting. Candid, cordial and constructive on Monday, and now we get to Thursday and it's not," he said.

The next round of trade talks are expected to take place in Washington in September, but it appears both sides will be working from more entrenched positions.

North Korea

The Trump administration has not yet voiced concern about North Korea's recent spate of weapons tests, with Trump saying Thursday he has "no problem" with it.

"We'll see what happens. But these are short-range missiles. They're very standard."

During previous talks, both sides came to a tacit agreement that North Korea would stop testing intercontinental-range missiles that can reach most of the US homeland and nuclear weapons.

There was no agreement regarding shorter-range missiles or other weapons technology -- which Trump has acknowledged -- and North Korea has made no secret that it is continuing to move along with its other weapons system, according to Vipin Narang, a professor at MIT who specializes in nuclear security issues.

North Korean missile tests often serve multiple purposes, both political and technological, and North Korea has itself said the recent uptick is in part due to planned military exercises this month between South Korea and Washington and Seoul's acquisition of stealth fighter jets.

"This is a stark reminder that President Trump went to Panmunjom, shook Kim Jong Un's hand and said we're going to restart talks. And Kim Jong Un is basically saying with these tests, I need more than a handshake," Narang said.

"The worry now is if Kim Jong Un is trying to send a message, and it's not getting through, he has to dial up the volume."

But experts say they're equally worried about some of the technological advancements North Korea has shown off, and their potential application in longer-range systems.

The short-range ballistic missiles fired appear to be solid-fueled, meaning that they can be deployed faster than their liquid-fueled counterparts.

While North Korea usually test-fires missile by launching them at a high altitude and short distance, recent launches have been much lower and gone further -- experts say that exposes them to much more environmental stress. Successfully conducting these tests better demonstrates viability and is a more realistic simulation of how they would be used if deployed against an adversary.

"Trump made the big mistake of giving these missiles a pass," said Duyeon Kim, an adjunct senior fellow at the Center for New American Security.

"Trump may be trying (to) keep negotiation alive, but by dismissing short-range ballistic missiles, he's allowing Pyongyang to strengthen and further build its arsenal and he's telling South Koreans and Americans living there that they don't matter."

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The missile launched on July 25 may have had the capability of maneuvering in-flight -- a development that makes the weapon much harder to track and helps it evade missile defense -- according to South Korean lawmakers briefed by the country's National Intelligence Service.

Only a handful of countries have developed these types of systems, said Adam Mount, the director of the Defense Posture Project at the Federation of American Scientists.

Mount said the current situation was "darker than anyone understands yet," adding that the President's comments Thursday on the launch were misleading.

"He (Trump) said that these missiles are standard. They're not standard, they are advanced systems that have several unusual and sophisticated features that pose major deterrence challenges," Mount said.

South Korea and Japan

On top of the issues with North Korea and China, Washington is also dealing with a dispute between South Korea and Japan that could threaten both security and economic relationships in the region.

On Friday, Japan dropped South Korea as a so-called preferred trading partner, escalating a dispute that threatens the global supply chain for smartphones and electronic devices.

South Korea's ruling Democratic Party called Japan's Friday decision an "all-out declaration of economic war on our country."

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Though the only two liberal democracies in northeast Asia, Seoul and Tokyo have long had an acrimonious relationship that often traces its roots to Japan's colonization of the Korean Peninsula.

The recent spat began last month when Tokyo placed controls on exports of three chemical materials -- including those used to make computer chips -- to South Korea.

South Korea and Japan have in recent years looked to their common ally -- the United States -- to help resolve disputes.

US Secretary of State Mike Pompeo said he will meet with the foreign ministers of both countries Saturday. All three are in Bangkok for ASEAN meetings, but it's unclear how willing the US is to engage in mediation. Japanese Chief Cabinet Secretary Yoshihide Suga said earlier this week that the US has not offered any plan to mediate the talks.

"We're very hopeful that those two countries will together themselves find a path forward, a way to ease the tension that has risen between them over these past handful of weeks," Pompeo said Friday.