Trade Ambassador Robert Strauss said today he has given the Chinese three days to decide on the U.S. terms for a textile agreement, but he called chances of settlement "iffy."

"We have scraped out the bottom of the barrel and I have put a final paper on the table, it is an ultimatum . . . we have to be firm . . . But I have no idea if we will settle," President Carter's special trade envoy said. "I'd flip a coin on whether we succeed . . . it's iffy."

Strauss meets Tuesday with Chinese Vice Premier Deng Xiaoping (Teng Hsiao-ping) and Foreign Ministry Huang Hua, possible in an effort to break the impasse in the textile negotiations.

The American said he has given the Chinese until Thursday to accept or reject the U.S. position. "Then we will advise the president and he will make a decision to protect the national interest," he said in an interview.

Washington wants an agreement that will limit Chinese textile exports to the United States in order to protect the U.S. garment and textile industry from stiff Chinese competition and preserve American jobs. Without such an agreement, Congress is not likely to approve a Chinese American trade pact that was initialed May 14 by Commerce Secretary Juanita Kreps during a visit to China.

The two sides have been negotiating for about a month. Talks ended formally Friday with no agreement and chief negotiator Michael Smith said chances were "less than 50-50".

Strauss said: "We have been engaged in complicated and difficult textile negotiations since we arrived Saturday.

"It's easy to see the Chinese point of view. They feel there is so much we want them to buy and so little they have to sell. They find it difficult to understand that we cannot buy an unlimited amount of textiles." CAPTION: Picture, ROBERT STRAUSS . . . makes final offer