Iran's foreign minister said Thursday there is "no possibility" of negotiations with the United States to reduce spiralling tensions, Japan's Kyodo news agency reported.
"No, there is no possibility for negotiations," the news agency cited Mohammad Javad Zarif as telling reporters in Tokyo, where he is meeting with Japanese officials.
Kyodo said the comment was in response to a question on whether he would be open to bilateral talks with Washington aimed at easing tensions.
It did not immediately carry additional comments from Zarif.
The top Iranian diplomat, who met with Japan's Prime Minister Shinzo Abe on Thursday, earlier accused Washington of an "unacceptable" escalation in tensions, and said Tehran was showing "maximum restraint".
Washington withdrew a year ago from a nuclear deal with Tehran and re-imposed sanctions, prompting a deterioration in relations.
But the crisis has deepened in recent week, with the US deploying an aircraft carrier strike group and B-52 bomber to the Gulf over alleged threats from Iran.