U.S. President Donald Trump has touted his meeting with Chinese President Xi Jinping at the weekend as "far better than expected" — but several trade and investment experts said Beijing appears to have gained the upper hand in the trade war.

Trump and Xi agreed at the G-20 summit in Japan to withhold from slapping additional tariffs on each other's products as the two sides return to the negotiating table in a bid to finalize a trade agreement. In addition, Trump said he agreed to allow Huawei to purchase U.S. products and China will buy "large amounts" of American farm produce.

Washington had earlier announced a ban that restricts Huawei's ability to do business with U.S. firms due to national security concerns. Trump's apparently softer stance on the Chinese tech giant was seen by some observers as a major concession that the U.S. has granted China.

"It is looking like, so far, China is coming out as a winner from this G-20," Francesco Filia, chief executive and chief investment officer at asset management firm Fasanara Capital, told CNBC's "Squawk Box Europe" on Monday.

"It's not even clear what they gave up in order to get it," he said, noting there was a lack of details about what the two leaders agreed on at the meeting.

Trump on Twitter: I had a great meeting with President Xi of China yesterday, far better than expected. I agreed not to increase the already existing Tariffs that we charge China while we continue to negotiate. China has agreed that, during the negotiation, they will begin purchasing large....amounts of agricultural product from our great Farmers. At the request of our High Tech companies, and President Xi, I agreed to allow Chinese company Huawei to buy product from them which will not impact our National Security. Importantly, we have opened up negotiations...

Trump on Twitter: ....again with China as our relationship with them continues to be a very good one. The quality of the transaction is far more important to me than speed. I am in no hurry, but things look very good! There will be no reduction in the Tariffs currently being charged to China.

Filia is not the only one who has expressed skepticism over the U.S.-China trade developments.

Trump standing down on some of his threats to China was "one of the most concerning outcomes at the G-20," said Danielle DiMartino Booth, chief executive of research firm Quill Intelligence.

"It looks as if he obviously gave a lot of ground back to China," she told CNBC's "Squawk Box Asia" on Wednesday.