Hillary Clinton’s national lead over Donald Trump has narrowed by 2 percentage points over the last week, according to an NBC News/SurveyMonkey Weekly Election Tracking Poll released Tuesday.

The poll found Clinton leads Trump by only 4 percentage points -- 48 percent to 44 percent. After the Democratic National Convention in late July, Clinton led Trump by 10 percentage points.

In a four-way match-up involving third-party candidates, Clinton leads Trump by only 2 percentage points -- 42 percent to 40 percent. Eleven percent said they back Libertarian Gary Johnson and 4 percent support Green Party candidate Jill Stein.

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Trump is improving among independent voters, the poll found. Only a few weeks ago, Clinton had a double-digit lead over Trump with independents, but now she leads him by just 2 percentage points -- 38 percent to 36 percent.

The survey found 59 percent said they have an unfavorable view of Clinton and 60 percent said the same about Trump.

The poll surveyed 16,220 adults between September 5 and 11 with a 1.1 percentage point margin of error.