TOKYO — President Barack Obama says Russia has not abided by the spirit or the letter of an agreement reached in Geneva last week that aimed to ease tensions in eastern Ukraine.

Obama said “malicious and armed men” continue to take over buildings in eastern Ukraine. He said Russia has not stepped in to halt such actions by pro-Russian insurgents.

Obama made his remarks during a news conference with Prime Minister Shinzo Abe during his first stop of a four-country tour of Asia, a trip that threatened to be overshadowed by the standoff between Ukraine and Russia.

Obama’s caution came in the wake of a warning by the Russian foreign minister Wednesday that attacks on Russian citizens or interests in Ukraine would bring a firm response.