WASHINGTON

A UN spokesman confirmed Friday that a letter from Iran’s representation had been formally transmitted to both the Security Council and the General Assembly at Tehran’s request.

"I can tell you and reiterate yet again that we are very concerned about the heightened rhetoric we're seeing around the region by the heightened military activities, war games or ... military naval presence," Stephane Dujarric told a news conference.

His remarks came a day after Iran's permanent mission to the UN warned that Tehran would respond "decisively and proportionately" to any military aggression, stressing that the US would bear "full and direct responsibility" for the consequences.

"The Islamic Republic of Iran has repeatedly stated at the highest level that it neither seeks tension nor war and will not initiate any war," the mission said in a letter addressed to UN Secretary-General Antonio Guterres and the UN Security Council presidency.

Dujarric said the UN encourages both the US and Iran to continue engaging in diplomacy to settle their differences.

Earlier Friday, US President Donald Trump said he was "considering" a limited military strike to pressure Iran into a deal, without providing further details.