Iran's president said Friday the six-nation incentive package aimed at getting his country to halt uranium enrichment was a step forward in resolving the dispute over Iran's nuclear program.

Yet Mahmoud Ahmadinejad juxtaposed that positive message with one of defiance, repeating his questioning of the World War II slaughter of 6 million Jews that has drawn scorn and condemnation from the West.

"These Holocaust events need to be further investigated by independent and impartial parties," Ahmadinejad told reporters after meeting with Chinese President Hu Jintao in China's commercial hub of Shanghai.

Ahmadinejad's remarks on the incentives were the highest-level sign that Iran was preparing to negotiate over the package.

Backed by the United States, three European countries, Russia and China, the proposal called for negotiations with the U.S. — something Washington has long refused to consider — and offered other incentives on condition that Iran freeze its uranium enrichment program.

"Generally speaking, we're regarding this offer as a step forward and I have instructed my colleagues to carefully consider it," Ahmadinejad said.

A response to the package will come "in due time in line with the international interests of the Islamic Republic of Iran," he said, without indicating whether the country would consider suspending enrichment.

Israeli Vice Premier Shimon Peres said Friday that Iran will suffer deepening poverty and isolation if it spurns international appeals for it to halt its nuclear activity.

"Their choice is to keep the country poor and their arsenal rich. It cannot go on forever," Peres told reporters on the fringes of a conference in the Central Asian nation of Kazakhstan. "The speeches are very impressive, but the reality is very depressive."

Countrywatch:Iran

Attending the same meetings, Iran's deputy foreign minister, Said Abbas Irakchi, told reporters that Iran had some concerns about the proposal.

"We see a lot of positive things there, but there are some things that we don't understand and that raise questions," he said.

Neither Ahmadinejad or Irakchi said what problems Iran saw with the incentives.

Iran has sent mixed signals on how it would respond ever since the incentives were offered last month. Iran denies accusations by the U.S. and others that it is seeking to develop nuclear weapons, saying its program would only generate energy.

Supreme leader Ayatollah Ali Khamenei took a hard-line approach on Thursday, quoted on state television as saying: "The Islamic Republic of Iran will not succumb to these pressures."

American and European officials in Vienna on Thursday urged Tehran to freeze enrichment and stop withholding information about its nuclear program.

The chief U.S. delegate to the International Atomic Energy Agency, Gregory L. Schulte, warned that if Iran rejected the incentives, it could face "the weight of the Security Council."

In other remarks Friday, Ahmadinejad said Iran was not afraid of an Israeli attack over its nuclear program, and said evidence of the Holocaust widely accepted in Europe could not be trusted.

"An event that has influenced so many diplomatic and political equations of the world needs to investigated and researched by impartial and independent groups," Ahmadinejad said.

In previous remarks, Ahmadinejad has dismissed the Holocaust as a "myth" and said Israel should be "wiped off the map."