Baghdad, Iraq ? Vice President Dick Cheney said Wednesday that “we’ve got a long way to go” in reducing violence in Iraq in a trip punctuated by an explosion that shook windows at the U.S. Embassy, where Cheney was visiting.

The vice president urged that Iraq’s parliament abandon plans for a two-month summer vacation while U.S. forces are fighting. With important issues pending, including how to share Iraq’s oil wealth, “any undue delay would be difficult to explain,” Cheney said.

As Democrats clamor for an end to the four-year-old war and President Bush sags in the polls, the White House is under intense political pressure to show that Prime Minister Nouri al-Maliki’s government is making progress. Cheney urged Iraq’s leaders to do more to reduce violence and promote political reconciliation.

White House counselor Dan Bartlett said in Washington that Cheney’s trip “gives an opportunity at a very high level for this message to be delivered.”

Eight days after Bush vetoed a bill setting deadlines for U.S. troop withdrawals from Iraq, the White House also served notice that Bush would veto a follow-up bill drafted by House Democratic leaders that would pay for the Iraq war only into summer. At the same time, Defense Secretary Robert Gates held out hope that troops can begin withdrawing if the Iraqi government makes progress by fall.

Supporters of radical Shiite cleric Muqtada al-Sadr rallied in Baghdad and Shiite areas to the south to protest the Cheney visit and demand the withdrawal of American forces. Protesters in Baghdad and the holy city of Najaf chanted “No to the occupation” and “No to America.”

Baghdad was Cheney’s first stop on a weeklong trip to the Middle East to seek support from moderate Arab leaders for help in bringing stability to Iraq. The vice president, joined by Gen. David Petraeus, the top U.S. commander in Iraq, and Ambassador Ryan Crocker, met with Iraqi political and military leaders.

“I emphasized the importance of making progress on the issues before us, not only the security issues but also on the political issues that are pending before the Iraqi government,” Cheney said.

Cheney spent most of the day at the U.S. Embassy inside the heavily protected Green Zone in central Baghdad. He was in the building when an explosion rattled windows and prompted officials to move reporters accompanying Cheney to the basement for several minutes.