(Bloomberg) — The United Arab Emirates said it “regrets” being included in the European Union’s list of alleged tax havens.

The Arab world’s second-largest economy was blacklisted despite its efforts to stay out of the group of 15 jurisdictions including neighboring Oman and small island nations. Its request for additional time to implement tax reforms was rejected.

The “inclusion was made despite the U.A.E.’s close cooperation with the EU on this issue and ongoing efforts to fulfill all the EU’s requirements,” state-run WAM news agency said.

The decision means U.A.E. residents and companies will face additional scrutiny and due diligence when conducting financial transactions in the European bloc, according to David Daley, partner at Gulf Tax Accounting Group in Dubai.

“The decision could impose laborious and time-consuming procedures for firms or people moving funds or buying property in the EU if they reside or earn in the U.A.E.,’’ he said. “However, I think the market will adapt fairly quickly.’’

The blacklist also includes American Samoa, Guam, Samoa, Trinidad and Tobago and U.S. Virgin Islands. New entrants are Aruba, Barbados, Belize, Bermuda, Dominica, Fiji, Marshall Islands, Oman and Vanuatu.