Democratic US presidential candidate Hillary Clinton smiles during a campaign rally in Columbus, Ohio, US, June 21, 2016.[Photo/Agencies]

NEW YORK - Democrat Hillary Clinton's lead over Republican rival Donald Trump has slipped by about five percentage points since mid-June, according to a Reuters/Ipsos poll released on Tuesday, bringing the race for the White House to within nine points.

The poll showed that 44.5 percent of likely voters supported former secretary of state Clinton while 35.5 percent backed businessman Trump. That compares with 46.6 percent support for Clinton and 32.3 percent for Trump on June 12, a date that marked her widest lead for the month.

Trump has focused much of his energy in recent days on the mass shooting in Orlando, Florida by a US-born gunman pledging allegiance to Islamic State militant group. Trump vowed to ban people from entering the United States from countries with links to terrorism against America or its allies.

Hardline national security proposals have help Trump win increased support from voters in the past, including after the shootings in San Bernardino, California and Paris late last year.

Clinton responded to the Orlando attack by calling for increased intelligence gathering and air strikes on Islamic State forces, while warning against demonizing American Muslims. She has also criticized Trump's positions on foreign policy and the economy, saying a Trump presidency would be a "disaster".

The June 17-21 poll of 1,100 likely voters has a credibility interval, a measure of accuracy, of 3.4 percentage points.