The Defence Ministry has confirmed reports that Cambodia has hired a US-based lobbying firm to wage what it described as an "information war" aimed at swaying international opinion against Thailand amid the ongoing border dispute.

Thailand is stepping up efforts to inspect domestic shipping vessels in a bid to prevent fuel and military supplies being diverted to Cambodia as the border tension between the two nations persists.

Thailand said on Tuesday that Cambodia must be first to announce a truce to halt fighting between the two nations

Thailand said it’s taking steps to restrict exports of fuel and arms through a checkpoint with Laos on fears the goods are being diverted to Cambodia as the border clash between the two countries intensifies.

The two sides are battling over longstanding competing claims to patches of frontier land, some of which contain centuries-old temple ruins.

Once scarred by war and genocide, Cambodia’s progress has been built on peace, the resilience of its people and foreign direct investment that has fueled a growing private sector.

The move came as China’s government urged both nations to exercise “utmost restraint” and de-escalate tensions.