GENEVA - The United States is abusing decision-making at the World Trade Organization (WTO) by holding hostage the selection process of new members to the Appellate Body, said Chinese Ambassador to the WTO Zhang Xiangchen in a meeting here on Tuesday.

The Appellate Body functions as the WTO's de facto court of appeals and is composed of seven members. However, only four of the seven members are in office since Washington refuses to initiate the process to fill vacancies.

"If the selection process is not launched, the functioning of the Appellate Body will be paralyzed, which will put the entire dispute settlement system in crisis," Zhang warned in a WTO General Council meeting.

He estimated that the WTO dispute settlement system is facing the most difficult time since its creation, underlining that "without such system, the WTO's trade rules will no longer be effectively enforced, and the trust and credibility of the multilateral trading system will be deeply undermined."

"Ultimately, we will not be able to effectively restrain unilateralism and protectionism," he added.

While Washington has expressed its concerns about the WTO dispute settlement system many times, Zhang said China cannot agree to link those concerns with the selection process.

"The member-driven mechanism does not mean that it is driven by only one single member," he said.

Any concern with respect to the system can and should be addressed through discussion under the WTO framework, he said, adding "China is willing to engage in such discussion".

On Monday, WTO Director-General Roberto Azevedo also urged members to step up their engagement towards tackling a number of systemic challenges, including the blockage of the nomination to the Appellate Body.

He said it was of "utmost importance" that members work to resolve the impasse regarding nominations. "If we do not find a solution here -- whatever shape that solution may take -- we could severely compromise the whole multilateral trading system," said Azevedo, urging members to relate to each other in "a solution-finding mode".