(CNN) The Trump administration on Thursday issued its first set of sanctions aimed at North Korea since the failed summit last month between Kim Jong Un and President Donald Trump, going after two Chinese shipping companies that have helped Pyongyang evade restrictions imposed by the US and United Nations Security Council.

A senior administration official told CNN that this action should not be seen as a sign the US is ramping up economic pressure on North Korea but as part of the continuous push to ensure that entities and countries are not taking their foot off the gas pedal.

"It is really meant to be a continuous activity of the US, and it really needs to a continuous activity of ... all of the UN members to maintain the integrity of the sanctions," the official said.

In Hanoi, the North Koreans wanted the majority of sanctions lifted in return for some action on denuclearization. It was their aggressive demand for substantial sanctions relief, coupled with unclear commitments on denuclearization, that sank any possible deal.

With these new sanctions, the Trump administration is reiterating that it will not cede to North Korea's demands. Instead, it is reminding companies like the Chinese ones targeted Thursday that they will not get away with any illicit activity with Pyongyang.

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