Noting that Russia had its quota of launching 16 US satellites this year, State Department spokesman James Rubin said yesterday ``if we don't get any progress on the missile proliferation problem, we are not going to be able to support increasing that quota''.

Interrupting the programme could cost the Russians several hundred million dollars annually, said Rubin. ``The economics of working with the US are better than with Iran,'' said Rubin.

This is not the first time that the US has threatened to disrupt its cooperation with Russia. Secretary of State Madeleine Albright brought up the issue in a meeting with her Russian counterpart, Igor Ivanov, at a December NATO meeting in Brussels.

``The focus was on Iranian missiles, it is a matter of extreme importance for the US,'' a senior official said then. Washington has been angered by Moscow's decision to furnish Iran with nuclear and ballistic technology, and its decision to sign a contract to deliver nuclear reactors.

Iran, meanwhile, has denied US allegations that it has been engaged in missile and nuclear coopearation with three Russian scientific and research institutes at the same time alleged the US statements as an attempt to violate Tehran's right to use nucler technology for peaceful purposes.

A statement issued by the Iranian embassy here on Wednesday said the allegations were a mere repetition of old accusations already denied by both Iranian and Russian officials.

The statement said that Iran had no knowledge of the Russian institutes except that there were a number of its students studying in Moscow university. ``Iran has no other connection and cooperation with the university,'' it added.

The statement by US National Security Advisor Sandy Berger was aimed at diverting public opinion from Washington's `unsparing support to the zionist regime which is a potential threat to peace in the region', Iran said.