US President Barack Obama has blamed conservative Republicans in the House of Representatives for not being able to reach a deal that would avoid an imminent default on US national debt.

At the White House, Mr Obama said the steep budget cuts Republicans insisted on as the price of an increase in the debt limit would do economic harm.

He called for an approach that would also raise taxes on wealthy Americans.

The US risks default on its $14.3tn (£8.7tn) debt unless a deal to raise the borrowing limit is reached by 2 August.