President Donald Trump is becoming increasingly concerned that his meeting with North Korean leader Kim Jong-Un could evolve into a political embarrassment, The New York Times reported Sunday.

According to foreign officials and people from the Trump administration who spoke with the Times, Trump was shocked by the statement from North Korea’s head nuclear negotiator last week that indicated total denuclearization of the Korean peninsula was not going to happen.

The President has reportedly been talking to aides about whether he should move forward with the historic meeting. On Saturday night, he called South Korean President Moon Jae-in — the Washington Post was first to report — to discuss the North’s latest statement and why it was in contradiction with private conversations Moon has had with Kim. Officials told the Times that the call, just three days before Moon was set to travel to Washington, D.C., is a signal of Trump’s unease surrounding the meeting.

According to aides who spoke with the Times, Trump has made no specific indication that he is planning to pull out of the talks, but officials are concerned that Trump has been too publicly eager about the meeting — like his remark that “everyone thinks” he should win a Nobel Peace Prize for the historic summit.

Trump is set to meeting with Kim in Singapore next month.

Read the Times’ full report here.