In less than one week, the US has finalized a $1.4 billion arms sale to Taiwan, labeled China one of the world's worst human traffickers and imposed sanctions on a Chinese bank for doing business with North Korea.
"It's a very firm indication that the honeymoon after the Mar-a-Lago summit is over and that tweet in particular ... that was a clear signal that there was going to be a change and cooling in temperature of China and US ties," Euan Graham, International Security Program director at Sydney's Lowy Institute, told CNN.
Sanctions placed on Chinese bank
On Thursday, the Trump administration announced plans to go ahead with a $1.4 billion arms sale to Taiwan
originally signed by the Obama administration. The unexpected timing of the deal -- which comes while Xi is in Hong Kong commemorating the 20th anniversary of the city's return to China
-- surprised many analysts.
The agreement, which was always likely to have gone ahead, appeared to have been at least temporarily shelved, as Trump looked to build closer ties with China. It's sudden reemergence will likely have angered Beijing, which considers Taiwan a rogue province and part of mainland China.
The sale came the same day as new sanctions were announced on China's Bank of Dandong
, which the US accuses of supporting illegal North Korean financial activity. On Tuesday, a new US government report labeled China as one of the world's worst offenders in human trafficking.
"From the beginning, President Trump has tied all these US-China issues together expecting cooperation from China on North Korea for cooperation from the US on these other issues," said Anthony Ruggiero, a North Korea expert and senior fellow at the Defense for Democracy.
Ruggiero said the decision to sanction Dandong was "long overdue," adding pressure could be put on China through their need for US currency.
"China is now in a position where it must defend a bank the US said is a money laundering concern. The Chinese leadership will wonder if the Trump administration will sanction a medium-sized Chinese bank next," he said.''
US officials call for North Korea containment
The decision to step up pressure on China comes as several prominent Trump administration officials have warned further action was needed against North Korea's nuclear missile program.
On Wednesday, US ambassador to the United Nations Nikki Haley labeled estimates that North Korea was "three to five years from developing a long-range nuclear weapon capable of reaching the US" as "optimistic."
The same day, US National Security Adviser HR McMaster publicly confirmed military options had been prepared to deal with North Korea.
"What we have to do is prepare all options because the President has made clear to us that he will not accept a nuclear power in North Korea, and a threat that can target the United States and target the American population," McMaster told a Washington think tank.
North Korea was a prominent topic of discussion when Trump welcomed South Korean President Moon Jae-in
at the White House Thursday night, although the Korean leader favors a diplomatic approach rather than military engagement.
"It is significant that (the sanctions) occurred on the afternoon of Moon's visit," Ruggiero told CNN. "This becomes a line in the sand that leaves the idea for engagement with North Korea open to discussion, but when it comes to pressure, shows the US will do as much as it can."
Taiwan arms deal long expected
Taiwan's Ministry of Defense said in a statement Friday morning they were "sincerely grateful" for the US decision to go ahead with the arms deal.
"The arms sale was proposed by our country last year. The package includes eight types of equipment and system, which will boost our combat capabilities in air and sea," the statement said.
China's ambassador to the US Cui Tiankai furiously denounced the sale in Chinese state media People's Daily, saying it violated the agreed upon "one China" policy.
"China has made strong protests to the US and will reserve the right to take further measures," state media quoted him as saying.
Zhang Baohui, professor of political science at Lingnan University, said until this week many high-profile Taiwanese had believed the US was moving away from them.
"(This arms deal) didn't go through for a while and some people suspected it was due to Trump's so-called reliance on China to resolve the North Korea issue ... so I think this arms sale could boost confidence (in US)," he said.
Zhang said this arms package, originally begun under former President Obama, was smaller than the last US arms deal with Taiwan, while Graham told CNN the actual contents of the newly approved Taiwanese arms deal were not especially provocative.
"They're not talking about major front line aircraft or major breakthroughs in technology, I think it's consistent with the Taiwan Relations Act and the provision of defense capabilities under that," Graham said.
"I don't see that alone as a provocation towards China, rather I think if we connect up these other areas, including sanctions on Chinese entities, that's the thing to watch."