VIENNA, Austria (AP) -- The U.N. nuclear watchdog agency on Friday suspended nearly half of the technical aid it now provides Iran, in line with U.N. sanctions slapped on the Islamic republic for its refusal to suspend its uranium enrichment program.

As IAEA chief Mohamed ElBaradei issued the report to his agency's 35-nation board, Iran's chief nuclear negotiator abruptly canceled planned meetings both with ElBaradei in Vienna and with senior European leaders in Munich, on the sidelines of a security conference in the German city.

Organizers of the Munich conference said negotiator Ali Larijani canceled because of an unspecified illness, while IAEA officials said they were told he was not coming for "technical reasons."

Larijani's meetings with German Foreign Minister Frank-Walter Steinmeier and Javier Solana, the chief foreign policy envoy for the European Union, would have been the first with senior Western officials since negotiations with Solana collapsed last year over Tehran's refusal to suspend enrichment, a potential pathway to nuclear arms.

One diplomat in Vienna who is familiar with the Iranian file suggested that Larijani's decision not to show could have been due to the refusal of other major European nations, like France or Britain, to meet with Larijani because of his country's continued nuclear defiance.

The Vienna-based IAEA had already suspended aid to Iran in five instances last month in line with Security Council sanctions calling for an end to assistance for programs that could be misused to make an atomic weapon. On Friday, the agency fully or partially suspended another 18 projects that it deemed could be misused. All the decisions are subject to review and approval by the 35-nation board of the IAEA next month.

Iran gets IAEA technical aid for 15 projects and 40 more that involve other countries. The suspensions were across the board but in the case of projects involving other countries affected only Iran.

A diplomat familiar with the issue said the United States -- along with key allies -- had been looking to have up to half of the projects involving only Iran canceled, restricted or more closely monitored.

A U.S. official said Washington's position on what projects should be affected was "very similar" to that of the European powers, Britain, France and Germany.

Visible strains
The United States, Russia, China, Britain, France and Germany all want Iran to stop its enrichment program and have acted as a group in trying to engage Tehran on the issue. But their approaches and priorities have differed over the past year -- resulting in often visible strains in what is meant to be a joint initiative.

Russian and Chinese reluctance to slap harsh sanctions on Tehran -- as initially demanded by Washington -- have created the greatest pressures. Both nations share economic and strategic interests with Iran.

Differences over how severely to punish Tehran for its refusal to suspend enrichment led to months of disputes before agreement was reached in December on a Security Council resolution imposing limited sanctions that fell short of the harsher measures the Americans had pushed for.

The sanctions include a review of technical aid to Iran -- programs meant to bolster the peaceful use of nuclear energy in medicine, agriculture or power generation and the suspensions outlined in Friday's report were in line with that specification.

In November, the board of the agency indefinitely suspended an IAEA project that would have helped Iran put safety measures in place for a heavy water reactor that, once completed, will produce plutonium. Most of the projects up for review at the March meeting, however, are for programs that have less obvious potential weapons applications.

They include cancer nuclear waste storage programs, management training courses, safety projects and requests for help in international nuclear licensing procedures.

The March meeting also will hear a separate report from ElBaradei expected to confirm that Iran has expanded its enrichment efforts instead of mothballing them -- a development that would empower the Security Council to impose stricter sanctions.