Iran has violated the rights of women, Christians and members of other religious groups and ethnic minorities on a massive scale, even as it seeks to negotiate with the West, according to a new UN report that details an explosion of executions, including state-sanctioned killing of juveniles.

Imprisonment and executions of Christians has continued -- even at an accelerated pace -- since the election of self-proclaimed moderate President Hassan Rouhani, according to Ahmed Shaheed, the United Nations special rapporteur on Iran. Nearly 100 Christians are currently imprisoned "due to their Christian faith and activities," Shaheed wrote. Christians who converted from Islam and are active in the underground house-church movement often come in for the most severe prosecution, he said.

“Authorities reportedly continued to target the leaders of house churches, generally from Muslim backgrounds," Shaheed wrote. "Christian converts also allegedly continue to face restrictions in observing their religious holidays.”

In 2014, 753 people were executed in the country, the most state-sanctioned killings since 2002. The grim tally includes the execution of 25 women and 13 juveniles.

Roughly half of the executions were for drug-related crimes and, according to Shaheed, fail to meet the international standard of “most serious crimes” required for use of the death penalty.

"The report is a sober reminder that Iran's government, which exports terrorism and seeks nuclear weapons, is also an egregious human rights violator," U.S. Sen. Mark Kirk, R-Ill., told FoxNews.com. "Far from being moderate, the Iranian regime persecutes women, Christians, Baha'is, and other ethnic and religious minorities, and systematically denies its citizen many freedoms that we take for granted."

Shaheed has aggressively chronicled Iran's abysmal human rights record, even as the U.S. and Western nations negotiate with Tehran over its nuclear weapons program.

“With every report that Dr. Shaheed releases, it becomes more and more evident how systematic human rights violations are structured under the Iranian dictatorship,” said Saba Farzan, executive director of Foreign Policy Circle, a strategy think tank in Berlin. “The world community with leadership by the Obama administration has thrown human rights under the Persian rug -- literally. Democracy promotion has been sacrificed for the sake of talking endlessly to those who oppress Iranians terribly."

Farzan said the U.S. and the other members of the P5+1, the global powers negotiating with Iran to remove sanctions in return for assurances about its nuclear program, should put human rights on the table when talks resume.

Morad Mokhtari, an Iranian human rights researcher at the New Haven, Conn.-based Iran Human Rights Documentation Center, told FoxNews.com that Iran’s regime now presents a “smiley face to Christians, but nothing has changed. It has become worse. With Ahmadinejad [Iran’s former president] you could see the enemy.”

Benjamin Weinthal reports on human rights in the Middle East and is a fellow at the Foundation for Defense of Democracies. Follow Benjamin on Twitter @BenWeinthal