President Moon Jae-in on Monday instructed aides to mobilize all possible measures to stabilize a supply of urea water solution amid growing public concerns about a worsening shortage of the key material used in diesel vehicles to reduce emissions due to tightened imports.

Moon also ordered aides to "make utmost diplomatic efforts to secure" urea water solution from foreign countries, presidential spokesperson Park Kyung-mee told reporters.

The government will take stern actions against illegal market activities surrounding urea water solution, Moon told aides, according to Park.

South Korea has been grappling with a shortage of urea water solution, known as diesel exhaust fluid, and its surging prices in recent weeks, since China tightened exports of fertilizers and related materials, including urea, in October amid a power crisis caused by a coal supply shortage.

South Korea heavily relies on China for its supply of urea water solution, as 97.6 percent of its import came from China in the first nine months of this year. (Yonhap)