Sri Lanka could be hauled before a war crimes tribunal over the alleged killing of ‘many thousands of civilians’ in the final months of its separatist war with Tamil rebels, a top US official says.

In the toughest warning since the end of fighting in May 2009, US Assistant Secretary of State for South and Central Asian Affairs, Robert Blake, said Sri Lanka risked a forced international investigation, Sky News reported today.

Blake, a former ambassador to Sri Lanka, said it was ‘preferable’ for Sri Lanka to have its own investigation in line with internationally accepted human rights standards, rather than face an external inquiry.

‘It’s important to say that if Sri Lanka is not willing to meet international standards regarding these matters, there would be pressure to appoint an international commission to look into these things,’ said Robert Blake.

In a video interview on Monday from Washington, Blake said reconciliation, accountability and human rights were among the key elements the US wanted to see to normalise ties with the South Asian nation.

‘The UN has estimated that many thousands of civilians were killed in the final few months of the war,’ Blake said.

Blake cited the UN Security Council reporting Libya to the International Criminal Court last week as a signal of global concern over human rights.

He said he was not comparing Sri Lanka with Libya, but said the security council’s unanimous decision against Libya over the weekend underscored the resolve of the international community regarding crimes against humanity, Sky News reported in its website.