Mottaki made the remarks on Al Arabiya television today. But he said the talks must be well prepared.
On May 3 in Egypt, Mottaki and Rice greeted one another during a lunch at a conference on stabilizing Iraq.
Lower-ranking U.S. and Iranian officials met during the conference for a brief chat.
A spokesman for the Iranian Foreign Ministry also said today that Iran and Britain want to improve bilateral ties.
Their relations were strained last month after Iran detained 15 British service personnel.