Pochettino continued to add that "seven points will be hard with three games to play, but in football you have to try your best, " before reinstating that "it is true it will be difficult".
West Ham turned on the style to foil a Tottenham side usually so energetic and menacing to ease any lingering relegation fears.
"I'm calm but disappointed of course because we missed a chance to close the gap on Chelsea", he said.
Home keeper Adrian frustrated Tottenham with first-half saves in quick succession from Dele Alli and Harry Kane and he also did well to keep out Son Heung-Min after the break as the visitors probed for an opener.
Tottenham, meanwhile, won't play again until May 14 when they take on Manchester United. I thought we got what we deserved.
In a quirk of the fixtures, Sunderland are set to play a big part in determining who goes down with them to the Championship.
LONDON - Tottenham Hotspur captain Hugo Lloris has said that Friday's defeat at West Ham was the result of complacency and not being strong enough mentality, describing the performance at the London Stadium as "difficult to accept". "We tried, it was hard".
North Korea missile launch tests Trump's China outreach
The missile, launched at a steep angle, reached an altitude of 2000km and travelled about 700km, landing in the sea west of Japan. But its arsenal is growing, so too the pace of its tests and its threats to carry out a seventh nuclear test.
And Spurs boss Pochettino admitted: "It's hard to be focused on Chelsea".
Eric Dier's header from the resulting corner forced Adrian to make another alert stop, but moments later Tottenham were lucky not to fall behind. We played well and these points were very important for us.
Spurs managed just 11 attempts on goal during the London derby in Stratford, as Pochettino's side suffered only their fourth loss of the season.
Who else? Lanzini missed one early chance and was clattered by Hugo Lloris before he could latch on to a second but the Argentinian's persistence paid off as he slotted home the victor with 25 minutes left.
SLAVEN BILIC was delighted that his "game plan" after his West Ham United side produced arguably their best performance of the season to see off bitter London rivals by a goal to nil at the London Stadium.
Spurs trailed 2-1 against the Hammers after 89 minutes at White Hart Lane earlier in the season, only to win 3-2.