THE HAGUE, Netherlands – Iran threatened yesterday to resume its uranium enrichment program if talks with European nations this week fail.

The comments put pressure on European negotiators before Iran’s talks in London on Friday with political leaders from France, Germany, and Britain.

Speaking after a meeting with his Dutch counterpart, Iranian Foreign Minister Kamal Kharrazi said Friday’s talks were critical.

“If talks with the European Union are not successful tomorrow, negotiations will collapse and we will have no choice but to restart the uranium enrichment program,” Mr. Kharrazi said yesterday.

France, Britain, and Germany have been negotiating with Iran, seeking guarantees that it won’t use its nuclear program to make weapons, as Washington suspects. Tehran insists the program – kept secret for two decades – is only for peaceful energy purposes.

Iran agreed in November to freeze uranium enrichment, but insists the move is temporary.

The European countries have been trying to get Iran to make it permanent. But last week, a spokesman for Iran’s Foreign Ministry said the country plans to resume uranium enrichment regardless of what comes out of the negotiations. Hamid Reza Asefi said then the freeze was not “a matter of a year, but months.”

Mr. Kharrazi said Iran is not willing to accept what he called “delay tactics” by the Europeans and that his country has a right to nuclear technology.

Dutch Foreign Minister Ben Bot said Europe wanted “objective guarantees that Iran’s uranium program is exclusively for peaceful purposes.”

Iran has argued that the Nuclear Nonproliferation Treaty, of which it is part, allows it to pursue a peaceful nuclear program, including enriching uranium. Uranium enriched to low levels can be used as fuel in nuclear reactors to generate electricity, but further enrichment makes it suitable for a nuclear bomb.

Mr. Kharrazi said yesterday that his country “has no weapons program” and that the International Atomic Energy Agency had found no proof to the contrary.