WASHINGTON - THE United States has warned Beijing over reported use of Chinese weapons by insurgents in Iraq and Afghanistan as well as the Asian giant's continued sale of arms to Iran, Deputy Secretary of State John Negroponte said on Thursday.

He said he conveyed the concerns personally to Chinese officials during his visit to Beijing this week.

'Just the other day, Monday, when I was in Beijing, this was one of the issues I raised - concern about Chinese weapons or Chinese-designed weapons showing up in some of these battle areas, be it Iraq or Afghanistan,' he told a congressional hearing on US-China ties.

The US military has repeatedly accused Iranian-linked groups of training Iraqi extremists in the use of armour piercing weapons known as explosively-formed penetrators (EFPs).

Afghan authorities had also seized dozens of Iranian and Chinese-made weapons from Taleban fighters near the border with Iran.

The weapons, including land mines and rocket-propelled grenades, appeared to have been manufactured in Iran and China, reports have said.

Mr Negroponte told the US senators that Washington 'made it clear' to Beijing that Chinese entities' continued sale of conventional weapons to Iran 'is unacceptable.'

He said that China understood the US position that Iran presented 'a grave international and regional security concern, and that our government reserves the right to apply all multilateral, bilateral and unilateral measures at our disposal to ensure that our concerns are addressed.

'We reinforce this message at every opportunity,' he said. -- AFP