6. National regulatory authorities shall be empowered to intervene on their own initiative in order to ensure compliance with this Regulation. National regulatory authorities or other competent authorities in the situations referred to under Article 61(2), points (b) and (c), of Directive (EU) 2018/1972, shall, where necessary, make use of the powers under Article 61 of that Directive to ensure adequate access and interconnection in order to guarantee the end-to-end connectivity and interoperability of roaming services, for example where customers are unable to exchange regulated roaming SMS messages with customers of a terrestrial public mobile communications network in another Member State as a result of the absence of a wholesale roaming agreement enabling the delivery of those messages.