Standard Chartered has reported a drop in profits after it wrote off $1bn (£650m) from the value of its Korean business.

The bank said pre-tax profit fell almost 16% to $3.3bn in the six months to the end of June, compared to $3.9bn for the same period a year ago.

The bank said Korea was its “most difficult market”. Excluding the write-off, profit edged up 4%.

Chairman Sir John Peace said the bank remained “confident for the long term”.

“The external environment will remain challenging for the foreseeable future, but we are in the right markets and have the right strategy in place to deliver growth,” he added.

The London-listed bank, which makes over 90% of its profits in Asia, Africa and the Middle East, said it had seen “excellent performances” from Hong Kong, India and Africa.

In Hong Kong, pre-tax profit was over $1bn for the first time in a six-month period.

The bank, which was fined $667m by US regulators last year for breaching sanctions on Iran and three other countries, said it continued to both review and enhance its compliance controls and processes.

“As a bank with over 88,000 employees in 70 markets, we cannot afford to be complacent,” Mr Peace said.

Richard Hunter, head of equities at Hargreaves Lansdown Stockbrokers, described the results as a “robust set of numbers”.

“Standard is well positioned to benefit from strong emerging market growth as it arises,” he said.