"But as we move forward, the Iraqi people should know that they will have the unwavering support of President Bush and the United States in consolidating their democracy."
Cheney praised the Iraqi government's legislative successes, but during his meeting with Nuri al-Maliki he also pointed to the items left unfinished.
He acknowledged that there remains much difficult work to be done in Iraq, where 160,000 American troops are deployed and the US death toll is near 4,000.
Cheney later spent the night at a US military base, his second overnight stay in Iraq.
Iraq was not on Cheney's announced schedule for a 10-day Middle East trip that includes stops in Oman, Saudi Arabia, Israel, the Palestinian territories and Turkey.
Cheney's visit comes as Iraq's sectarian factions are meeting amid concern that insufficient progress has been made on the path to reconciliation.
The two-day national unity conference began in Baghdad on Tuesday.
Ali al-Dabbagh, the Iraqi government spokesman, said the gathering aimed to achieve "security, reconstruction and complete sovereignty".
"Different political leaders will be present and the conference will aim to activate the role of different groups in the political process for positive contribution and national reconciliation," he said.