The United States on Tuesday exempted Japan and 10 EU nations from financial sanctions because they have significantly cut purchases of Iranian crude oil, but left Iran's top customers, China and India, exposed to the possibility of such steps.

Banks of the 11 countries have been given a six-month reprieve from the threat of being cut off from the US financial system under new sanctions designed to pressure Iran over its nuclear program.

The list, however, excludes China and India, Iran's top two crude oil importers, and South Korea and Turkey, which are also among the top-10 consumers of Iranian oil.

If China, India and others do not significantly cut Iranian imports by the end of July, the US law will enable President Barack Obama to impose sanctions.

Hong Lei, China's Foreign Ministry spokesman, reiterated Beijing's position in response to the announcement by US Secretary of State Hillary Clinton.

He said at Wednesday's regular news conference that China consistently stands against unilateral sanctions based on a country's domestic laws and will not accept similar sanctions imposed on a third country.

"What China is doing has not violated the relevant resolutions of the UN Security Council and never impaired the interests of any third party and the international community," Hong said, adding that China's interaction with Iran is "fair, reasonable and legal".

China has imported Iranian oil for economic development through regular channels, he said.

Japanese Finance Minister Jun Azumi welcomed the decision and said Japan would continue to cut its imports of Iranian oil at a set rate in the future.

"The decision takes account of Japan's steps on Iranian oil, including its future response," he told reporters at a regular briefing.

The US State Department Special Envoy and Coordinator for International Energy Affairs Carlos Pascual cited Japan's estimated 15 to 22 percent cut in oil purchases from Iran in the second half of last year as an example for other nations.

Pascual declined to set a benchmark for countries to secure a 180-day exemption from the US financial sanctions, but he noted that the US law says they must "significantly reduce" oil imports from Iran and must continue to do so to win future exemptions.

The 10 nations from the European Union, which has already decided to stop importing Iranian oil beginning in July, were Belgium, Britain, the Czech Republic, France, Germany, Greece, Italy, the Netherlands, Poland and Spain, the State Department said.

Meanwhile, Iran's Supreme Leader Ayatollah Ali Khamenei said that Teheran will retaliate against any attack by Israeli or US forces "on the same level".

Khamenei made the remarks in an address just moments after Obama appealed directly to the Iranian people with a message of solidarity.

The contrasting approaches on Tuesday highlighted the broad range of political posturing and tactics as the standoff deepens over Teheran's nuclear program.

Khamenei repeated his claims that the country does not seek atomic weapons, but said all of Iran's conventional firepower was ready to respond to any attack.

"We do not have atomic weapons and we will not build one. But against an attack by enemies we will attack them on the same level that they attack us," he said.

China Daily-AP