The Trump campaign said Thursday that it is filing a lawsuit in federal court in Nevada on Thursday, asking the judge to stop counting ballots due to "thousands" of illegal ballots.

Richard Grenell, former acting director of National Intelligence, addressed reporters at a press conference, claiming that the campaign was not being allowed to observe the process.

"Ballots are not automatically legal votes until they are checked and we are not being allowed to check," Grenell said. 

It is election officials, not campaigns, that verify voters' ballots. Both Republican and Democratic poll watchers are observing ballot counting in Nevada.

MSNBC reporter Jacob Soboroff pressed Grenell for evidence. Watch what happened next.

Joe Biden’s lead over President Trump in the pivotal battleground state of Nevada grew to nearly 12,000 votes Thursday afternoon, as votes continued to be counted in Clark County.

As of 12:30 p.m. ET, Biden led Trump in Nevada 603,807 votes to 592,020, or by a margin of 11,787 votes, according to NBC News’ Decision Desk. Eighty-eight percent of the vote in Nevada has been counted, according to NBC News' Decision Desk. Nevada and its six Electoral College votes remained too close to call as of 12:30 p.m. ET.

Biden’s expanded lead — earlier in the day he’d led Trump by fewer than 8,000 votes — came as Clark County, which includes Las Vegas, continued to count ballots. 

Biden's campaign on Thursday again predicted he would prevail, saying the vote counts in Nevada and Pennsylvania would put him past the finish line.

“Our data shows that Joe Biden will be the next president of the United States,” Biden campaign manager Jen O’Malley Dillon said Thursday during a virtual briefing with reporters. She added that the continued counting of votes in key battlegrounds “is going to show our path to victory.”

In Nevada, where Biden is currently leading Trump by about 8,000 votes, with 86 percent of the vote in, O’Malley Dillon said she expected counting “to be finished and results to be announced” Thursday.

In Pennsylvania, she said, Biden would win by a “sizable number of votes."

She called Georgia a “true toss-up” but said that Biden had been “cutting into” Trump’s lead and that the state now “leans to the vice president.”

Above all, O’Malley Dillon said supporters need to “stay patient” and “stay calm.”

“The counting is happening. It’s going to take time,” she said. 

Campaign adviser Bob Bauer said the multiple lawsuits filed by the Trump campaign in numerous states were all “meritless” and designed “to create an opportunity for them to message falsely about what is happening in the election process.”

He added that the suits are “doomed to fail.”

Gabriel Sterling, the chief operating officer of the Georgia secretary of state’s office, told reporters at a Thursday morning press conference that he thinks his state will finish counting ballots by the end of the day.

“We anticipate getting through this process today,” he said at the state capitol in Atlanta. 

The state has about 61,000 uncounted ballots. Sterling attributed the ballot counting delays to some county staffers accidentally forgetting to press an upload button to the system. 

“Fast is great. We appreciate fast. We more appreciate accuracy,” he said, adding that election officials "are not involved in voter fraud; these people are not involved in voter suppression." 

Pennsylvania Lt. Gov. John Fetterman said that his state’s ballot-counting process is “drawing to a close” and believes that the outstanding ballots will deliver the state's 20 electoral votes to Joe Biden.

As of Thursday morning, Pennsylvania had about 768,000 ballots remaining that needed to be counted, which Fetterman said in an interview on MSNBC would be enough to "probably deliver our Commonwealth to the [former] vice president at this point, based on previous modeling of how those ballots have been performing with respect to, whether it's for the [former] vice president, or the president.”

While Fetterman declined to predict when he believes his state would finish counting, he indicated that it was possible it would be done by Thursday evening.

“Things are drawing to a close,” said Fetterman, who reiterated that the outstanding ballots in his state will be favorable to Biden’s chances to carry Pennsylvania, which Trump won in 2016.

Asked about any irregularities from the election in his state, he said it’s been “incredibly smooth” and suggested that the only issue has been the lawsuits the Trump campaign is mounting.

“You have the Trump campaign showing up on our corner in Philadelphia like some sad carnival barker, making outlandish claims,” he said. “That's the only problem.”

Democrat Mark Kelly has claimed victory against Republican Sen. Martha McSally in Arizona, which would give Democrats a badly needed pickup in the Senate if the vote returns bear out that result.

"I am deeply honored that Arizonans have trusted me to be their next United States Senator and to serve in this seat once held by Senator John McCain," Kelly said in a series of tweets Wednesday night.

"We woke up today still facing a pandemic, a struggling economy, and deep division in our country," he wrote. "We need to slow the spread of the virus, get our economy back on track, and defend health care protections for people with pre-existing conditions. And I know that together, we can."

McSally has not conceded the race, and NBC News is characterizing the race as too early to call, with Kelly leading.

A win would give the state two Democratic senators, Kelly and Kyrsten Sinema, who was elected in 2018. Sinema congratulated Kelly in a tweeted statement Wednesday. "I am confident Mark will uphold the Arizona values of seeking common ground and putting country above party," she wrote. 

Kelly, 56, is a former NASA astronaut and the husband of former Rep. Gabby Giffords, who survived being shot in the head in 2011 at a constituent event. The couple founded the Giffords Foundation, which supports gun control laws around the country.

There are 62,000 outstanding votes in Georgia, the secretary of state’s office told NBC News on Thursday.

Secretary of State Brad Raffensperger is holding a press conference later Thursday morning.

This race is still too close to call.