The United States would be making a mistake if it attacked Tehran, Iran’s envoy said.

“If they hit us from any location we will strike back from any location,” Iranian ambassador Seyed Mahmoud-Reza Sajjadi told a news conference in Moscow.

Sajjadi was speaking amid increasing tensions over Iran’s disputed uranium enrichment program. Western powers suspect Iran is seeking to create a nuclear bomb and have tightened sanctions. Tehran says it only wants to produce its own energy.

Iranian President Mahmoud Ahmadinejad announced on Wednesday what he described as major advances in Tehran’s nuclear program. In an elaborate ceremony aired on state TV, Ahmadinejad presided over the loading of Iran’s first domestically-made nuclear fuel rods into a research reactor.

Speculation has also been growing in recent weeks that Israel may be preparing to attack OPEC’s No. 2 oil exporter to counter what it views as a serious threat to its national security. The United States has also refused to rule out force.

Sajjadi also said Iran had no role in blasts targeting Israeli diplomats in Thailand, India and Georgia earlier this week.

Israel has accused Iran of masterminding the attacks which injured a total of nine people.

“[Israel] wants to pass this as a tit-for-tat move in response to attacks of Israeli intelligence on Iranian nuclear scientists,” Sajjadi said.

Last month, Mostafa Ahmadi-Roshan, an academic who worked at Iran’s Natanz uranium enrichment facility, became the fourth scientist associated with Tehran’s disputed nuclear program to have been assassinated since 2010.

Iran says the United States and Israel were behind the incidents but both countries deny the accusations.

The Iranian envoy also said the European Union “made a mistake” by agreeing to stop importing Iranian oil from July 1.

“If buyers of oil are able to announce an embargo, so are its suppliers,” Sajjadi told the Moscow news conference.

Iran has also warned that it may cut off oil exports to six European countries in response to the latest sanctions against the regime and also threatened to close the Strait of Hormuz, through which some 40 percent of the world’s tanker-borne oil exports pass.