By Matt Spetalnick MARTINSBURG, W.Va., July 4 (Reuters) - U.S. President George W. Bush, trying to tap into Independence Day patriotism to rally support for an unpopular war, appealed on Wednesday for American patience and resolve in Iraq. In a Fourth of July holiday speech at a West Virginia Air National Guard base, Bush said "we all long for the day" when there are fewer U.S. troops in Iraq but insisted that more time is needed for his Iraq strategy to work. "Victory in this struggle will require more patience, more courage and more sacrifice," Bush, flanked by a giant American flag, told a crowd of more than 1,000 National Guard personnel and family members gathered inside an aircraft hanger. With his approval ratings stuck at the lows of his presidency, Bush is under increasing pressure for positive results from a U.S. troop buildup in Iraq as he seeks to prevent further defections by fellow Republicans skeptical of his handling of the war. The administration's sense of urgency has increased in the countdown to a much-awaited September progress report on a Baghdad security crackdown spearheaded by deployment of about 28,000 additional troops since the start of the year. Amid unrelenting bloodshed in Iraq and scant signs of progress by the Iraqi government in meeting political benchmarks, the White House has sought to temper any expectations of rapid strides from the troop increase. Democrats controlling Congress have made clear they hope to use the September report as a lever to push for a timetable for troop withdrawal, something Bush has firmly rejected. "Withdrawing prematurely, based on politics ... will not be in our national interest," Bush said. "That's something we're not yet going to do. But as the 2008 presidential campaign revs up, some of Bush's fellow Republicans are increasingly at odds with him over the Iraq war, which polls show most Americans oppose.