The confusing state of talks to end the U.S.-China trade war just got murkier with the participation of presidential son-in-law Kared Kushner as a trade negotiator. Kushner is currently senior White House advisor to president Donald Trump.

White House sources cited by U.S. media say Kusnher -- who is married to Ivana Marie (Ivanka), Trump's favorite daughter -- has kept increasing his direct involvement in the U.S.-China trade negotiations over the past two weeks. Kushner has again met with Cui Tiankai, China's ambassador to the United States. Kushner and Cui have met many times since Trump took office, establishing a kind of back-channel relationship, according to U.S. trade experts.

A White House official confirmed Kushner's involvement in the stalled talks but refused to provide specific details on the influence he's had, if any, on the negotiations.

"Jared has been engaged in the process from the beginning in full coordination and in support of Ambassador Lighthizer's and Secretary Mnuchin's efforts," said the White House official.

Some analysts saw Kushner's belated participation as a clear sign the moribund trade talks might be nearing a conclusion. They noted Kushner acts as a kind of interpreter of what Trump will find acceptable in a trade deal. They also said Kushner has worked well with U.S. Trade Representative Robert Lighthizer, the trade talk's lead negotiator, and Cui.

Kushner apparently received his father-in-law's blessing because of his role in the successful negotiations that led to U.S.-Mexico-Canada trade agreement (USMCA). This trade deal still has to be ratified by the U.S. Congress, however. USMCA replaces the North American Free Trade Agreement or NAFTA.

Kushner, who once called the president "a black swan," is said to have played a key role in the later stages of USMCA negotiations, helping resolve final differences. Lighthizer said the USMCA deal "would not have happened if it wasn't for Jared."

Former Mexican foreign Minister Luis Videgaray said Kushner patched-up the negotiations more than once after they threatened to fall apart. Lighthizer and Treasury Secretary Steven Mnuchin lead the U.S. negotiating team seeking a compromise with Chinese negotiators led by Vice Premier Liu He. Fruitless talks have endured for more than a year.

Trump on Tuesday admitted it won't be possible to reach a comprehensive trade deal with China before the 2020 U.S. presidential election in November. His dismaying comment made in London is the clearest indication yet the trade war with China he boasted in 2018 would be "easy to win" is no nearer to a resolution. It was only last week Trump claimed he's in the "final throes of an important deal" while bragging about his alleged friendship with president Xi Jinping.

Trump said it might be better to wait until after the 2020 election to strike a trade deal with China.

"In some ways, I like the idea of waiting until after the election for the China deal, but they want to make a deal now and we will see whether or not the deal is going to be right," said Trump.