LONDON, United Kingdom - In its reply to a recent letter by US President Donald Trump, Iran has said it will not start a war and seeks peace and stability in the region, according to the country's highest-ranking commander Maj. Gen. Mohammad Bagheri.

"But we will respond to any threat with full force," Bagheri declared, addressing a commanders' meeting in Tehran on Sunday, as reported by Tasnim news agency. 

Trump's letter, conveyed to Tehran by senior Emirati diplomat Anwar Gargash, has called on the Iranian leadership to come to the negotiating table over Tehran's nuclear program. 

Iran's reply was "measured, firm and befitting", Bagheri said, in apparent reaction to reports that Trump's letter had carried a threatening tone. 

According to Bagheri, Iran's response stressed that it has never sought nuclear weapons ambitions, but will pursue "the demands of our nation."

The Islamic Republic has long insisted that its nuclear program is designed for peaceful and civilian purposes. 

The International Atomic Energy Agency (IAEA), however, has in multiple reports highlighted Iran's near weapons-grade enrichment at a 60 percent purity levels, warning that it is on the cusp of producing atomic bombs. 

In his reply, Supreme Leader Ayatollah Ali Khamenei has also noted that Iran will not agree to direct negotiations, but "takes no issue" with indirect dialogue. The line was once again echoed by Foreign Minister Abbas Araghchi on Sunday, as he noted "direct talks will be meaningless." 

The commander added that Khamenei had described Trump as a promise-breaker, "in whom there is no trust," reminding the American leader of his pullout in 2018 from the Iran nuclear deal—formally known as the Joint Comprehensive Plan of Action (JCPOA). 

The remarks by the top general, who denounced Trump as a "narcissist and bullying figure," came amid an intensifying US military build-up in the region. 

The reinforcement has seen B2 bombers, F35 fighter jets, and aircraft carriers deployed to the Persian Gulf as well as the Indian Ocean island of Diego Garcia in what appears to be preparation for possible strikes on Iranian nuclear sites—should diplomacy fail to resolve the standoff.