Britain says it will stand alongside the U.S. in supporting an upcoming ruling by an international tribunal in a case that challenges the legality of China's expansive territorial claims in the South China Sea.

Beijing says the Permanent Court of Arbitration in the Hague, which is hearing the case, has no jurisdiction in the matter. The case was brought by the Philippines in 2013 and a ruling is expected by mid-year.

Hugo Swire, British minister of state for the foreign office, told a Washington think tank Monday that growing tensions in the South China Sea are driven by China's assertive actions. He said any ruling by the court should be binding on both parties.

Swire pushed back against perceptions that Britain is unwilling to challenge Beijing because it wants Chinese investment.