Ecuador said Tuesday it would soon begin temporarily requiring visas for Chinese citizens, after it noted a "worrying increase" in the number who overstay their authorized time in the country.

Starting July 1, Quito will suspend the bilateral agreement that had allowed Chinese citizens to stay in Ecuador for up to 90 days without applying for a visa, the foreign ministry said.

"In recent months, there has been a worrying increase in migratory flows from China," the ministry said in a statement, provided in Spanish and English on social media.

"Additionally, approximately 50 percent of these entries have not left through regular routes and within the times established by law," it said.

Between January and May of this year, Ecuador recorded 17,808 Chinese nationals entering the country, but only 9,966 exiting it, according to government figures.

The ministry said some of these visitors have been using Ecuador as a starting point for reaching other destinations in the hemisphere, without specifying which countries.

China is one of Ecuador's main trade partners and, under the government of former Ecuadoran president Rafael Correa, also became its largest lender.