BRIEF-Canadian PM Trudeau says he does not want USMCA negotiations reopened

Canadian Prime Minister Justin Trudeau, speaking to reporters in Washington on Thursday, says: * VERY PLEASED WITH EXISTING USMCA PACT, CONCERNED THAT IF IT IS REOPENED IT COULD LEAD TO LENGTHY RENEGOTIATIONS AND WORSE OUTCOMES

* HE HAD A VERY GOOD CONVERSATION WITH HOUSE SPEAKER PELOSI ON USMCA PACT, SAYS CANADA WONT GET INVOLVED IN U.S. RATIFICATION PROCESS * AFTER BEING ASKED WHETHER HE PRESSED TRUMP TO RAISE CASE OF TWO DETAINED CANADIANS WITH CHINESE PRESIDENT, TRUDEAU DOES NOT ANSWER DIRECTLY Further company coverage: (Reporting by Steve Scherer)