Leaders of the United States, China and other Group of 20 major economies who meet this weekend say more trade would shore up sluggish global growth but are tightening their own controls on imports.
S Leaders どんな→[of] the United States
(other Group of 20 major) economies どんな→ [who] meet
いつ→ this weekend
S (more) trade
V [would shore up]
O (sluggish global) growth
V [are tightening]
O (their own) controls どんな→ [on] imports.