He said so in an interview with BBC World in Davos, Switzerland.
The PM also said Sri Lanka would attempt to reach trade agreements with Britain after the Brexit, even if the country regained the GSP+.
Within the commonwealth, discussions would be held with New Zealand to strengthen trade and investment as well, he said.
Wickremesinghe also said that police officers had to be given foreign training to investigate allegations of serious acts of corruption and fraud during the previous regime.
He charged that supporters of ex-president Maithripala Sirisena were responsible for the protests in Hambantota against Chinese investments, adding that those demonstrations had led to a division among the Rajapaksa supporters.