Dhaka: United Nations Secretary General Ban Ki-moon has written letters to Prime Minister Sheikh Hasina and BNP Chairperson Khaleda Zia seeking their joint efforts to resolve the ongoing political crisis to maintain Bangladesh's impressive socio-economic progress.

However, it could not be confirmed whether he called for dialogue between the two leaders as means of solution.

When asked whether the UN chief has called for dialogue, UN Deputy Spokesman for the Secretary General Farhan Haq said that the UN chief has written two leaders recently.

"The Secretary General has recently sent letters to the two leaders, saying that Oscar Fernandez Taranco is acting on his behalf," he said in an email communication on Tuesday night.