Talking tough: Powell joins the hawks on Iraq
Mr Powell said the United States' priority was to defeat the al-Qaeda network, which it blames for the 11 September attacks on New York and Washington, and its Taleban protectors in Afghanistan.
He said that after defeating al-Qaeda: "We will turn our attention to terrorism throughout the world, and nations such as Iraq, which have tried to pursue weapons of mass destruction, should not think that... we will not turn our attention to them."
The statement seemed to mark a shift for Mr Powell, who said last month that the US had no immediate plans to attack Iraq, although it would "deal with terrorism around the world".
Mr Powell's comments appeared to align his views with those of US Defense Secretary Donald Rumsfeld, seen as more hawkish than Mr Powell who is often viewed as a moderating influence in Washington, analysts said.
Mr Powell made the statement during a news conference with Kuwait's acting Prime Minister, Sabah al-Hamad al-Sabah, who reaffirmed his country's support for the US-led campaign against terrorism.
'Ridiculous threats'
Mr Powell was responding to reports that Iraq's Deputy Prime Minister, Tariq Aziz, still claimed Kuwait as Iraqi territory.
Iraq's invasion of Kuwait in 1990 triggered the Gulf War - in which the US and its allies drove out Iraqi forces and restored Kuwait's government.
Mr Powell dismissed the possibility that Iraq would again invade Kuwait.
"Mr Tariq Aziz has been making these rather ridiculous and threatening statements for many years, so I take them all with a grain of salt," Mr Powell said.
Mr Aziz said last month that he expected the US and Britain to attack Iraq, using the war against terrorism as an excuse to try to overthrow Iraqi leader Saddam Hussein.
A newspaper run by Mr Hussein's son said a few days later that Iraq might come under attack after the Western allies suspended operations in Afghanistan because of winter.