John Kerry’s job is being made harder by the run-up to the 2016 election.

The US secretary of state—America’s chief diplomat—has finally opened up about the impact of some of the comments made by presidential hopefuls on the campaign trail. While not naming any candidate, Kerry admitted that world leaders and foreign diplomats are growing increasingly concerned. He told “Face the Nation“:

I think it is fair to say that they’re shocked. It upsets people’s sense of equilibrium about our steadiness, about our reliability, and to some degree I must say to you, some of the questions, the way they’re posed to me, it’s clear to me that what’s happening is an embarrassment to our country.

It unlikely that it’s Kerry’s fellow Democrats, Bernie Sanders and Hillary Clinton, they are worried about.

Ted Cruz has called for “law enforcement to patrol and secure Muslim neighborhoods before they become radicalized.” Republican frontrunner Donald Trump, who says America hasn’t been great in 116 years, has called for Muslims to be barred from entering the US, a wall to be built with Mexico, and purchases of Saudi oil to be halted if they don’t do more to fight terror. Soon after the terrorist attacks in Pakistan yesterday (March 27), Trump boldly tweeted that he alone can solve the problem.

Trump has angered many foreign diplomats, with officials from Europe, the Middle East, Latin America, and Asia reportedly making private complaints about some of the candidate’s comments, Reuters reported. US officials said that it was highly unusual for diplomats to comment on US presidential candidates—as they’re mindful they’ll have to work with whoever wins.

That said, a number of world leaders have not held back when it comes to Trump. British prime minister David Cameron described Trump’s anti-Muslim rhetoric as “divisive, stupid, and wrong,” while French prime minister Manuel Valls criticized Trump for encouraging hatred against Muslims.

Valls tweeted: “Mr. Trump, like others, stokes hatred: our ONLY enemy is radical Islamism.” The Turkish president and a Saudi prince also denounced the Republican presidential frontrunner, with the latter tweeting describing Trump as “a disgrace.”

No wonder Kerry is embarrassed.