China and Mexico both signaled a willingness to negotiate with Washington over escalating trade issues, while the Trump administration took to the airwaves to defend its use of tariffs to gain concessions from trading partners.

Beijing released on Sunday a government policy paper on trade issues, accusing Washington of scuttling the negotiations, which broke down in all but name in May. It said the Trump administration’s “America First” program and use of tariffs are harming the global economy and that China wouldn’t shy away from a trade war if need be. But throughout the document and at a briefing, the government suggested a willingness to return to negotiations.

“We’re willing to adopt a cooperative approach to find a solution,” Vice Commerce Secretary Wang Shouwen said in Beijing on Sunday.

Mexico, meanwhile, rushed a delegation to the U.S. to discuss immigration issues, following the Trump administration’s threat last week to impose tariffs on all Mexican goods entering the U.S. if the Mexican government fails to take aggressive measures to stem the flow of immigrants through Mexico and into the U.S.

“Mexico is sending a big delegation to talk about the Border,” President Trump wrote on Twitter on Sunday afternoon. “Problem is, they’ve been “talking” for 25 years. We want action, not talk. They could solve the Border Crisis in one day if they so desired.”