William Hague told the House of Commons that there had been secret experiments with missiles and rocket launchers. "Iran has ... been carrying out covert ballistic missile tests and rocket launches, including testing missiles capable of delivering a nuclear payload," Hague said in a statement covering the Middle East and North Africa.
Iran has said it intends to triple its capacity to produce 20 percent enriched uranium, "levels far greater than is needed for peaceful nuclear energy," he said.
Britain believes Tehran has conducted at least three secret tests of medium-range ballistic missiles since October.
"These tests are provocative acts, directly contrary to Iran's obligations under U.N. (Security Council Resolutions)," a spokesman for the British Foreign and commonwealth Office told msnbc.com.
Iran, at loggerheads with the West over its nuclear program, is carrying out a 10-day military exercise in a show of strength it hopes will warn Israel and the United States against any attack. The U.S. and its allies insist it is aimed at developing atomic weapons — a charge Iran rejects.
A senior Iranian Revolutionary Guard commander said Tuesday that his country has the ability to produce missiles with an even greater range than those currently in its arsenal. But Amir Ali Hajizadeh, commander of the Guard's Aerospace Force, stressed that Tehran will not manufacture such missiles because Israel and U.S. bases in the Gulf are already within reach.