Russian Foreign Minister Sergei Lavrov says Moscow is “extremely concerned” by US President Donald Trump’s stance on the 2015 nuclear deal between Iran and the six world powers, asserting that Russia would defend the landmark agreement as it has “genuinely strengthened both regional and international security.”

In his maiden speech at the United Nations General Assembly on Tuesday, Trump said the deal, known as the Joint Comprehensive Plan of Action (JCPOA), was “an embarrassment” to Washington.

“It’s extremely worrying,” said Lavrov, whose country is a signatory to the deal besides the US, the UK, France, China and Germany. “We will defend this document, this consensus, which was met with relief by the entire international community and genuinely strengthened both regional and international security.”

The Trump administration has desperately sought a pretext to scrap or weaken the JCPOA, which came into effect in January 2016 and put limitations on Iran’s peaceful nuclear program in exchange for removing nuclear-related sanctions against the Islamic Republic.

In his speech, the Republican president described the agreement as “the worst and most one-sided transaction the US has ever entered into,” a characterization he often used during his presidential campaign.

He told reporters on Wednesday that he had made his decision about staying in the agreement but declined to reveal it.

Tehran rebuked Trump’s rhetoric, with Iranian Foreign Minister Mohammad Javad Zarif describing it as an “ignorant hate speech” that was “unworthy of a reply.”

French President Emmanuel Macron and EU foreign policy chief Federica Mogherini also reiterated their commitment to the nuclear greement.

US threats ‘antagonizing’ North Korea

In his UN speech, Trump also made harsh comments about North Korea, threatening to “totally destroy” the country if it needed to.

Lavrov said the threats did not help and Washington had to change its rhetoric if it wanted to come to an agreement with Pyongyang.

“If you simply condemn and threaten, then we’re going to antagonize countries over whom we want to exert influence,” the Russian foreign minister said.

Last month, Trump prompted international concern after threatening the North with “fire and fury” over its ballistic missile and nuclear weapons tests.

US working on illegal weapons

Elsewhere in his speech, Lavorv rejected US claims that his country was in breach of the 1987 Intermediate-range Nuclear Forces (INF) treaty, which bans ground-launched Russian and American intermediate-range missiles.

He said if anyone was violating the treaty it was the US, which is in the midst of a $1-trillion, 30-year modernization of its aging ballistic missile submarines, bombers and land-based missiles.

“We have suspicions on at least three fronts that the Americans are creating weapons systems which violate or could violate the treaty obligations,” said Lavrov, who said Moscow had relayed its concerns to the United States.